Vulnerability-Lookup

RHSA-2026:25193

Vulnerability from csaf_redhat - Published: 2026-06-16 10:11 - Updated: 2026-06-18 20:01

Summary

Red Hat Security Advisory: OpenShift Container Platform 4.20.25 bug fix and security update

Severity

Critical

Notes

Topic: Red Hat OpenShift Container Platform release 4.20.25 is now available with updates to packages and images that fix several bugs and add enhancements. This release includes a security update for Red Hat OpenShift Container Platform 4.20. Red Hat Product Security has rated this update as having a security impact of Critical. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Details: Red Hat OpenShift Container Platform is Red Hat's cloud computing Kubernetes application platform solution designed for on-premise or private cloud deployments. This advisory contains the container images for Red Hat OpenShift Container Platform 4.20.25. See the following advisory for the RPM packages for this release: https://access.redhat.com/errata/RHBA-2026:25192 Space precludes documenting all of the container images in this advisory. See the following Release Notes documentation, which will be updated shortly for this release, for details about these changes: https://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html/release_notes/ Security Fix(es): * kernel: ip6_tunnel: clear skb2->cb[] in ip4ip6_err() (CVE-2026-43037) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. All OpenShift Container Platform 4.20 users are advised to upgrade to these updated packages and images when they are available in the appropriate release channel. To check for available updates, use the OpenShift CLI (oc) or web console. Instructions for upgrading a cluster are available at https://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html-single/updating_clusters/index#updating-cluster-cli.

Terms of Use: This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.

CVE-2026-43037

A flaw was found in the Linux kernel's IPv6 tunnel implementation. A remote attacker could exploit this flaw by sending malicious ICMPv6 error messages to cause a stack-based buffer overflow in the kernel's IPv4-over-IPv6 tunnel error handling code. This could result in a kernel crash (denial of service) or potentially allow arbitrary code execution with kernel privileges.

8.8 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE-843 - Access of Resource Using Incompatible Type ('Type Confusion')

Affected products

Fixed 4 products

Product	Version	Remediation
Unresolved product id: 9Base-RHOSE-4.20:rhcos-aarch64-4.20.9.6.202606101223-0	—	Vendor Fix fix Workaround
Unresolved product id: 9Base-RHOSE-4.20:rhcos-ppc64le-4.20.9.6.202606101223-0	—	Vendor Fix fix Workaround
Unresolved product id: 9Base-RHOSE-4.20:rhcos-s390x-4.20.9.6.202606101223-0	—	Vendor Fix fix Workaround
Unresolved product id: 9Base-RHOSE-4.20:rhcos-x86_64-4.20.9.6.202606101223-0	—	Vendor Fix fix Workaround

Threats

Impact Critical

References

10 references

URL	Category
https://access.redhat.com/errata/RHSA-2026:25193	self
https://access.redhat.com/security/updates/classi…	external
https://bugzilla.redhat.com/show_bug.cgi?id=2464351	external
https://issues.redhat.com/browse/OCPBUGS-77834	external
https://security.access.redhat.com/data/csaf/v2/a…	self
https://access.redhat.com/security/cve/CVE-2026-43037	self
https://bugzilla.redhat.com/show_bug.cgi?id=2464351	external
https://www.cve.org/CVERecord?id=CVE-2026-43037	external
https://nvd.nist.gov/vuln/detail/CVE-2026-43037	external
https://lore.kernel.org/linux-cve-announce/202605…	external

JSON

To clipboard

{
  "document": {
    "aggregate_severity": {
      "namespace": "https://access.redhat.com/security/updates/classification/",
      "text": "Critical"
    },
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Copyright \u00a9 Red Hat, Inc. All rights reserved.",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en",
    "notes": [
      {
        "category": "summary",
        "text": "Red Hat OpenShift Container Platform release 4.20.25 is now available with\nupdates to packages and images that fix several bugs and add enhancements.\n\n This release includes a security update for Red Hat OpenShift Container\nPlatform 4.20.\n\nRed Hat Product Security has rated this update as having a security impact\nof Critical. A Common Vulnerability Scoring System (CVSS) base score, which\ngives a detailed severity rating, is available for each vulnerability from\nthe CVE link(s) in the References section.",
        "title": "Topic"
      },
      {
        "category": "general",
        "text": "Red Hat OpenShift Container Platform is Red Hat\u0027s cloud computing\nKubernetes application platform solution designed for on-premise or private\ncloud deployments.\n\nThis advisory contains the container images for Red Hat OpenShift Container\nPlatform 4.20.25. See the following advisory for the RPM packages for this\nrelease:\n\nhttps://access.redhat.com/errata/RHBA-2026:25192\n\nSpace precludes documenting all of the container images in this advisory.\nSee the following Release Notes documentation, which will be updated\nshortly for this release, for details about these changes:\n\nhttps://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html/release_notes/\n\nSecurity Fix(es):\n\n* kernel: ip6_tunnel: clear skb2-\u003ecb[] in ip4ip6_err() (CVE-2026-43037)\n\nFor more details about the security issue(s), including the impact, a CVSS\nscore, acknowledgments, and other related information, refer to the CVE\npage(s) listed in the References section.\n\nAll OpenShift Container Platform 4.20 users are advised to upgrade to these\nupdated packages and images when they are available in the appropriate\nrelease channel. To check for available updates, use the OpenShift CLI (oc)\nor web console. Instructions for upgrading a cluster are available at\nhttps://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html-single/updating_clusters/index#updating-cluster-cli.",
        "title": "Details"
      },
      {
        "category": "legal_disclaimer",
        "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.",
        "title": "Terms of Use"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "https://access.redhat.com/security/team/contact/",
      "issuing_authority": "Red Hat Product Security is responsible for vulnerability handling across all Red Hat products and services.",
      "name": "Red Hat Product Security",
      "namespace": "https://www.redhat.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "https://access.redhat.com/errata/RHSA-2026:25193",
        "url": "https://access.redhat.com/errata/RHSA-2026:25193"
      },
      {
        "category": "external",
        "summary": "https://access.redhat.com/security/updates/classification/#critical",
        "url": "https://access.redhat.com/security/updates/classification/#critical"
      },
      {
        "category": "external",
        "summary": "2464351",
        "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2464351"
      },
      {
        "category": "external",
        "summary": "OCPBUGS-77834",
        "url": "https://issues.redhat.com/browse/OCPBUGS-77834"
      },
      {
        "category": "self",
        "summary": "Canonical URL",
        "url": "https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_25193.json"
      }
    ],
    "title": "Red Hat Security Advisory: OpenShift Container Platform 4.20.25 bug fix and security update",
    "tracking": {
      "current_release_date": "2026-06-18T20:01:18+00:00",
      "generator": {
        "date": "2026-06-18T20:01:18+00:00",
        "engine": {
          "name": "Red Hat SDEngine",
          "version": "5.0.0"
        }
      },
      "id": "RHSA-2026:25193",
      "initial_release_date": "2026-06-16T10:11:44+00:00",
      "revision_history": [
        {
          "date": "2026-06-16T10:11:44+00:00",
          "number": "1",
          "summary": "Initial version"
        },
        {
          "date": "2026-06-16T10:11:44+00:00",
          "number": "2",
          "summary": "Last updated version"
        },
        {
          "date": "2026-06-18T20:01:18+00:00",
          "number": "3",
          "summary": "Last generated version"
        }
      ],
      "status": "final",
      "version": "3"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_name",
                "name": "Red Hat OpenShift Container Platform 4.20",
                "product": {
                  "name": "Red Hat OpenShift Container Platform 4.20",
                  "product_id": "9Base-RHOSE-4.20",
                  "product_identification_helper": {
                    "cpe": "cpe:/a:redhat:openshift:4.20::el9"
                  }
                }
              }
            ],
            "category": "product_family",
            "name": "Red Hat OpenShift Enterprise"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "rhcos-aarch64-4.20.9.6.202606101223-0",
                "product": {
                  "name": "rhcos-aarch64-4.20.9.6.202606101223-0",
                  "product_id": "rhcos-aarch64-4.20.9.6.202606101223-0",
                  "product_identification_helper": {
                    "purl": "pkg:generic/redhat/rhcos@4.20.9.6.202606101223?arch=aarch64"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "aarch64"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "rhcos-ppc64le-4.20.9.6.202606101223-0",
                "product": {
                  "name": "rhcos-ppc64le-4.20.9.6.202606101223-0",
                  "product_id": "rhcos-ppc64le-4.20.9.6.202606101223-0",
                  "product_identification_helper": {
                    "purl": "pkg:generic/redhat/rhcos@4.20.9.6.202606101223?arch=ppc64le"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "ppc64le"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "rhcos-s390x-4.20.9.6.202606101223-0",
                "product": {
                  "name": "rhcos-s390x-4.20.9.6.202606101223-0",
                  "product_id": "rhcos-s390x-4.20.9.6.202606101223-0",
                  "product_identification_helper": {
                    "purl": "pkg:generic/redhat/rhcos@4.20.9.6.202606101223?arch=s390x"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "s390x"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "rhcos-x86_64-4.20.9.6.202606101223-0",
                "product": {
                  "name": "rhcos-x86_64-4.20.9.6.202606101223-0",
                  "product_id": "rhcos-x86_64-4.20.9.6.202606101223-0",
                  "product_identification_helper": {
                    "purl": "pkg:generic/redhat/rhcos@4.20.9.6.202606101223?arch=x86_64"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "x86_64"
          }
        ],
        "category": "vendor",
        "name": "Red Hat"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "rhcos-aarch64-4.20.9.6.202606101223-0 as a component of Red Hat OpenShift Container Platform 4.20",
          "product_id": "9Base-RHOSE-4.20:rhcos-aarch64-4.20.9.6.202606101223-0"
        },
        "product_reference": "rhcos-aarch64-4.20.9.6.202606101223-0",
        "relates_to_product_reference": "9Base-RHOSE-4.20"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "rhcos-ppc64le-4.20.9.6.202606101223-0 as a component of Red Hat OpenShift Container Platform 4.20",
          "product_id": "9Base-RHOSE-4.20:rhcos-ppc64le-4.20.9.6.202606101223-0"
        },
        "product_reference": "rhcos-ppc64le-4.20.9.6.202606101223-0",
        "relates_to_product_reference": "9Base-RHOSE-4.20"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "rhcos-s390x-4.20.9.6.202606101223-0 as a component of Red Hat OpenShift Container Platform 4.20",
          "product_id": "9Base-RHOSE-4.20:rhcos-s390x-4.20.9.6.202606101223-0"
        },
        "product_reference": "rhcos-s390x-4.20.9.6.202606101223-0",
        "relates_to_product_reference": "9Base-RHOSE-4.20"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "rhcos-x86_64-4.20.9.6.202606101223-0 as a component of Red Hat OpenShift Container Platform 4.20",
          "product_id": "9Base-RHOSE-4.20:rhcos-x86_64-4.20.9.6.202606101223-0"
        },
        "product_reference": "rhcos-x86_64-4.20.9.6.202606101223-0",
        "relates_to_product_reference": "9Base-RHOSE-4.20"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-43037",
      "cwe": {
        "id": "CWE-843",
        "name": "Access of Resource Using Incompatible Type (\u0027Type Confusion\u0027)"
      },
      "discovery_date": "2026-05-01T00:00:00+00:00",
      "ids": [
        {
          "system_name": "Red Hat Bugzilla ID",
          "text": "2464351"
        }
      ],
      "notes": [
        {
          "category": "description",
          "text": "A flaw was found in the Linux kernel\u0027s IPv6 tunnel implementation. A remote attacker could exploit this flaw by sending malicious ICMPv6 error messages to cause a stack-based buffer overflow in the kernel\u0027s IPv4-over-IPv6 tunnel error handling code. This could result in a kernel crash (denial of service) or potentially allow arbitrary code execution with kernel privileges.",
          "title": "Vulnerability description"
        },
        {
          "category": "summary",
          "text": "kernel: ip6_tunnel: clear skb2-\u003ecb[] in ip4ip6_err()",
          "title": "Vulnerability summary"
        },
        {
          "category": "other",
          "text": "This Critical flaw in the Linux kernel\u0027s IPv6 tunneling error handling can lead to a stack buffer overflow. An unauthenticated remote attacker could exploit this by sending specially crafted network packets, potentially resulting in a denial of service or information disclosure on affected Red Hat Enterprise Linux systems.",
          "title": "Statement"
        },
        {
          "category": "general",
          "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product\u0027s status, and are included for informational purposes to better understand the severity of this vulnerability.",
          "title": "CVSS score applicability"
        }
      ],
      "product_status": {
        "fixed": [
          "9Base-RHOSE-4.20:rhcos-aarch64-4.20.9.6.202606101223-0",
          "9Base-RHOSE-4.20:rhcos-ppc64le-4.20.9.6.202606101223-0",
          "9Base-RHOSE-4.20:rhcos-s390x-4.20.9.6.202606101223-0",
          "9Base-RHOSE-4.20:rhcos-x86_64-4.20.9.6.202606101223-0"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://access.redhat.com/security/cve/CVE-2026-43037"
        },
        {
          "category": "external",
          "summary": "RHBZ#2464351",
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2464351"
        },
        {
          "category": "external",
          "summary": "https://www.cve.org/CVERecord?id=CVE-2026-43037",
          "url": "https://www.cve.org/CVERecord?id=CVE-2026-43037"
        },
        {
          "category": "external",
          "summary": "https://nvd.nist.gov/vuln/detail/CVE-2026-43037",
          "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43037"
        },
        {
          "category": "external",
          "summary": "https://lore.kernel.org/linux-cve-announce/2026050102-CVE-2026-43037-0346@gregkh/T",
          "url": "https://lore.kernel.org/linux-cve-announce/2026050102-CVE-2026-43037-0346@gregkh/T"
        }
      ],
      "release_date": "2026-05-01T00:00:00+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-06-16T10:11:44+00:00",
          "details": "For OpenShift Container Platform 4.20 see the following documentation,\nwhich will be updated shortly for this release, for important instructions\non how to upgrade your cluster and fully apply this asynchronous errata\nupdate:\n\nhttps://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html/release_notes/\n\nYou may download the oc tool and use it to inspect release image metadata\nfor x86_64, s390x, ppc64le, and aarch64 architectures. The image digests\nmay be found at\nhttps://quay.io/repository/openshift-release-dev/ocp-release?tab=tags.\n\nThe sha values for the release are as follows:\n\n      (For x86_64 architecture)\n      The image digest is sha256:490002f6d1363683178f4b9999f52602588f3cb75a9267a190fdfdee06e2db7a\n\n      (For s390x architecture)\n      The image digest is sha256:4b17edb77f71d8f32fab03e233a63b13eae84de232535a3386b44c9bf2dbb95b\n\n      (For ppc64le architecture)\n      The image digest is sha256:9154fd7ab04d202ecb43304419e5974acad03f16a9c5b61f52f8841dd310269d\n\n      (For aarch64 architecture)\n      The image digest is sha256:ce5d55048f0cbbe54394a24c37e54435e1c5032252eee4dfaa1d684fe00f7cd4\n\nAll OpenShift Container Platform 4.20 users are advised to upgrade to these\nupdated packages and images when they are available in the appropriate\nrelease channel. To check for available updates, use the OpenShift CLI (oc)\nor web console. Instructions for upgrading a cluster are available at\nhttps://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html-single/updating_clusters/index#updating-cluster-cli.",
          "product_ids": [
            "9Base-RHOSE-4.20:rhcos-aarch64-4.20.9.6.202606101223-0",
            "9Base-RHOSE-4.20:rhcos-ppc64le-4.20.9.6.202606101223-0",
            "9Base-RHOSE-4.20:rhcos-s390x-4.20.9.6.202606101223-0",
            "9Base-RHOSE-4.20:rhcos-x86_64-4.20.9.6.202606101223-0"
          ],
          "restart_required": {
            "category": "none"
          },
          "url": "https://access.redhat.com/errata/RHSA-2026:25193"
        },
        {
          "category": "workaround",
          "details": "Mitigation for this issue is to skip loading the affected module `ip6_tunnel` onto the system till we have a fix available, this can be done by a blacklist mechanism, this will ensure the driver is not loaded at the boot time.\n~~~\nHow do I blacklist a kernel module to prevent it from loading automatically? \nhttps://access.redhat.com/solutions/41278  \n~~~\n\nWe may also want to detection and monitoring an affected system as below:\n~~~\nMonitor for exploitation attempts:\n\n# Enable kernel audit for IPv6 tunnel operations\nauditctl -a always,exit -F arch=b64 -S socket -F a0=10 -F a1=3 -k ipv6_tunnel\n\n# Monitor system logs for kernel panics/crashes\njournalctl -k -p err -f | grep -i \"ip6_tunnel\\|icmp\\|stack\"\n~~~",
          "product_ids": [
            "9Base-RHOSE-4.20:rhcos-aarch64-4.20.9.6.202606101223-0",
            "9Base-RHOSE-4.20:rhcos-ppc64le-4.20.9.6.202606101223-0",
            "9Base-RHOSE-4.20:rhcos-s390x-4.20.9.6.202606101223-0",
            "9Base-RHOSE-4.20:rhcos-x86_64-4.20.9.6.202606101223-0"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "products": [
            "9Base-RHOSE-4.20:rhcos-aarch64-4.20.9.6.202606101223-0",
            "9Base-RHOSE-4.20:rhcos-ppc64le-4.20.9.6.202606101223-0",
            "9Base-RHOSE-4.20:rhcos-s390x-4.20.9.6.202606101223-0",
            "9Base-RHOSE-4.20:rhcos-x86_64-4.20.9.6.202606101223-0"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Critical"
        }
      ],
      "title": "kernel: ip6_tunnel: clear skb2-\u003ecb[] in ip4ip6_err()"
    }
  ]
}

CVE-2026-43037 (GCVE-0-2026-43037)

Vulnerability from cvelistv5 – Published: 2026-05-01 14:15 – Updated: 2026-05-11 22:16

Title

ip6_tunnel: clear skb2->cb[] in ip4ip6_err()

Summary

In the Linux kernel, the following vulnerability has been resolved: ip6_tunnel: clear skb2->cb[] in ip4ip6_err() Oskar Kjos reported the following problem. ip4ip6_err() calls icmp_send() on a cloned skb whose cb[] was written by the IPv6 receive path as struct inet6_skb_parm. icmp_send() passes IPCB(skb2) to __ip_options_echo(), which interprets that cb[] region as struct inet_skb_parm (IPv4). The layouts differ: inet6_skb_parm.nhoff at offset 14 overlaps inet_skb_parm.opt.rr, producing a non-zero rr value. __ip_options_echo() then reads optlen from attacker-controlled packet data at sptr[rr+1] and copies that many bytes into dopt->__data, a fixed 40-byte stack buffer (IP_OPTIONS_DATA_FIXED_SIZE). To fix this we clear skb2->cb[], as suggested by Oskar Kjos. Also add minimal IPv4 header validation (version == 4, ihl >= 5).

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

8 references

URL	Tags
https://git.kernel.org/stable/c/ea9f65b27c8404e16…
https://git.kernel.org/stable/c/d6621f60192fe10c0…
https://git.kernel.org/stable/c/2cc6e3b0fe0f0242d…
https://git.kernel.org/stable/c/a0c4ce9900a108eaf…
https://git.kernel.org/stable/c/1063515ce15ff3106…
https://git.kernel.org/stable/c/590f622669b97eaf7…
https://git.kernel.org/stable/c/4a622658f384b0356…
https://git.kernel.org/stable/c/2edfa31769a4add82…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: c4d3efafcc933fd2ffd169d7dc4f980393a13796 , < ea9f65b27c8404e164848ebff1443310fd187629 (git) Affected: c4d3efafcc933fd2ffd169d7dc4f980393a13796 , < d6621f60192fe10c047a4487be42a6f4c150707f (git) Affected: c4d3efafcc933fd2ffd169d7dc4f980393a13796 , < 2cc6e3b0fe0f0242d1f530a93a4924f48ab85ba5 (git) Affected: c4d3efafcc933fd2ffd169d7dc4f980393a13796 , < a0c4ce9900a108eaf55d0f3b399cb55999647d39 (git) Affected: c4d3efafcc933fd2ffd169d7dc4f980393a13796 , < 1063515ce15ff31065c4e7f8265f4c2fd3c54876 (git) Affected: c4d3efafcc933fd2ffd169d7dc4f980393a13796 , < 590f622669b97eaf7b57a1de7b0a6e68c5d8b2c3 (git) Affected: c4d3efafcc933fd2ffd169d7dc4f980393a13796 , < 4a622658f384b03560834cbe8ffcfe69a278f7c8 (git) Affected: c4d3efafcc933fd2ffd169d7dc4f980393a13796 , < 2edfa31769a4add828a7e604b21cb82aaaa05925 (git)
Linux	Linux	Affected: 2.6.22 Unaffected: 0 , < 2.6.22 (semver) Unaffected: 5.10.253 , ≤ 5.10.* (semver) Unaffected: 5.15.203 , ≤ 5.15.* (semver) Unaffected: 6.1.168 , ≤ 6.1.* (semver) Unaffected: 6.6.134 , ≤ 6.6.* (semver) Unaffected: 6.12.81 , ≤ 6.12.* (semver) Unaffected: 6.18.22 , ≤ 6.18.* (semver) Unaffected: 6.19.12 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/ip6_tunnel.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ea9f65b27c8404e164848ebff1443310fd187629",
              "status": "affected",
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "versionType": "git"
            },
            {
              "lessThan": "d6621f60192fe10c047a4487be42a6f4c150707f",
              "status": "affected",
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "versionType": "git"
            },
            {
              "lessThan": "2cc6e3b0fe0f0242d1f530a93a4924f48ab85ba5",
              "status": "affected",
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "versionType": "git"
            },
            {
              "lessThan": "a0c4ce9900a108eaf55d0f3b399cb55999647d39",
              "status": "affected",
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "versionType": "git"
            },
            {
              "lessThan": "1063515ce15ff31065c4e7f8265f4c2fd3c54876",
              "status": "affected",
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "versionType": "git"
            },
            {
              "lessThan": "590f622669b97eaf7b57a1de7b0a6e68c5d8b2c3",
              "status": "affected",
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "versionType": "git"
            },
            {
              "lessThan": "4a622658f384b03560834cbe8ffcfe69a278f7c8",
              "status": "affected",
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "versionType": "git"
            },
            {
              "lessThan": "2edfa31769a4add828a7e604b21cb82aaaa05925",
              "status": "affected",
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/ip6_tunnel.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.22"
            },
            {
              "lessThan": "2.6.22",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.253",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.203",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.168",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.134",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.81",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.22",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.253",
                  "versionStartIncluding": "2.6.22",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.203",
                  "versionStartIncluding": "2.6.22",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.168",
                  "versionStartIncluding": "2.6.22",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.134",
                  "versionStartIncluding": "2.6.22",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.81",
                  "versionStartIncluding": "2.6.22",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.22",
                  "versionStartIncluding": "2.6.22",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.12",
                  "versionStartIncluding": "2.6.22",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "2.6.22",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_tunnel: clear skb2-\u003ecb[] in ip4ip6_err()\n\nOskar Kjos reported the following problem.\n\nip4ip6_err() calls icmp_send() on a cloned skb whose cb[] was written\nby the IPv6 receive path as struct inet6_skb_parm. icmp_send() passes\nIPCB(skb2) to __ip_options_echo(), which interprets that cb[] region\nas struct inet_skb_parm (IPv4). The layouts differ: inet6_skb_parm.nhoff\nat offset 14 overlaps inet_skb_parm.opt.rr, producing a non-zero rr\nvalue. __ip_options_echo() then reads optlen from attacker-controlled\npacket data at sptr[rr+1] and copies that many bytes into dopt-\u003e__data,\na fixed 40-byte stack buffer (IP_OPTIONS_DATA_FIXED_SIZE).\n\nTo fix this we clear skb2-\u003ecb[], as suggested by Oskar Kjos.\n\nAlso add minimal IPv4 header validation (version == 4, ihl \u003e= 5)."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T22:16:29.957Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ea9f65b27c8404e164848ebff1443310fd187629"
        },
        {
          "url": "https://git.kernel.org/stable/c/d6621f60192fe10c047a4487be42a6f4c150707f"
        },
        {
          "url": "https://git.kernel.org/stable/c/2cc6e3b0fe0f0242d1f530a93a4924f48ab85ba5"
        },
        {
          "url": "https://git.kernel.org/stable/c/a0c4ce9900a108eaf55d0f3b399cb55999647d39"
        },
        {
          "url": "https://git.kernel.org/stable/c/1063515ce15ff31065c4e7f8265f4c2fd3c54876"
        },
        {
          "url": "https://git.kernel.org/stable/c/590f622669b97eaf7b57a1de7b0a6e68c5d8b2c3"
        },
        {
          "url": "https://git.kernel.org/stable/c/4a622658f384b03560834cbe8ffcfe69a278f7c8"
        },
        {
          "url": "https://git.kernel.org/stable/c/2edfa31769a4add828a7e604b21cb82aaaa05925"
        }
      ],
      "title": "ip6_tunnel: clear skb2-\u003ecb[] in ip4ip6_err()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43037",
    "datePublished": "2026-05-01T14:15:35.314Z",
    "dateReserved": "2026-05-01T14:12:55.978Z",
    "dateUpdated": "2026-05-11T22:16:29.957Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

RHSA-2026:25193

CVE-2026-43037 (GCVE-0-2026-43037)

Tags

Sightings

Nomenclature