Vulnerability-Lookup

GHSA-QCCH-2R2R-XCW2

Vulnerability from github – Published: 2026-08-22 18:30 – Updated: 2026-08-25 06:31

Details

In the Linux kernel, the following vulnerability has been resolved:

ipvs: avoid out-of-bounds write in ip_vs_nat_icmp

Sashiko warns that local attacker can modify the packet while it is processed by IPVS. Some places read the IP ihl field multiple times which can cause out-of-bounds access. One such place is ip_vs_nat_icmp where we can write after the validated area.

Fix it by providing ciph argument just like it is done for IPv6 and use ciph->len as offset to the embedded transport header.

Modify some IPv4 header checks by reading the ihl field only once.

Severity

7.8 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-74724"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-22T16:16:47Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipvs: avoid out-of-bounds write in ip_vs_nat_icmp\n\nSashiko warns that local attacker can modify the packet\nwhile it is processed by IPVS. Some places read the\nIP ihl field multiple times which can cause out-of-bounds\naccess. One such place is ip_vs_nat_icmp where we\ncan write after the validated area.\n\nFix it by providing ciph argument just like it is done for\nIPv6 and use ciph-\u003elen as offset to the embedded transport\nheader.\n\nModify some IPv4 header checks by reading the ihl field\nonly once.",
  "id": "GHSA-qcch-2r2r-xcw2",
  "modified": "2026-08-25T06:31:30Z",
  "published": "2026-08-22T18:30:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74724"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/243d0187ec4c3837b9b0004f18d1068e46115760"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3b8f79af0e98f27b932b0b416e9c52b692d31ff9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3c779b258c9c3c3567af68d4f45c2f751f35bd0e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/646922a0379496154e8c8faca4f8e2fd9100cacc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a69a4b3fff5814d079beff9a1e9d369994b2ed47"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/be65fa324640c7a95e30b146159a2be5cc73f22e"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-74724 (GCVE-0-2026-74724)

Vulnerability from cvelistv5 – Published: 2026-08-22 15:33 – Updated: 2026-08-25 05:42

Title

ipvs: avoid out-of-bounds write in ip_vs_nat_icmp

Summary

In the Linux kernel, the following vulnerability has been resolved: ipvs: avoid out-of-bounds write in ip_vs_nat_icmp Sashiko warns that local attacker can modify the packet while it is processed by IPVS. Some places read the IP ihl field multiple times which can cause out-of-bounds access. One such place is ip_vs_nat_icmp where we can write after the validated area. Fix it by providing ciph argument just like it is done for IPv6 and use ciph->len as offset to the embedded transport header. Modify some IPv4 header checks by reading the ihl field only once.

Severity

7.8 (High)


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

Assigner

Linux mitre root

References

6 references

URL	Tags
https://git.kernel.org/stable/c/3b8f79af0e98f27b9…
https://git.kernel.org/stable/c/3c779b258c9c3c356…
https://git.kernel.org/stable/c/be65fa324640c7a95…
https://git.kernel.org/stable/c/a69a4b3fff5814d07…
https://git.kernel.org/stable/c/243d0187ec4c3837b…
https://git.kernel.org/stable/c/646922a0379496154…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 3b8f79af0e98f27b932b0b416e9c52b692d31ff9 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 3c779b258c9c3c3567af68d4f45c2f751f35bd0e (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < be65fa324640c7a95e30b146159a2be5cc73f22e (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < a69a4b3fff5814d079beff9a1e9d369994b2ed47 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 243d0187ec4c3837b9b0004f18d1068e46115760 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 646922a0379496154e8c8faca4f8e2fd9100cacc (git)
Linux	Linux	Affected: 2.6.12 Unaffected: 0 , < 2.6.12 (semver) Unaffected: 6.1.183 , ≤ 6.1.* (semver) Unaffected: 6.6.152 , ≤ 6.6.* (semver) Unaffected: 6.12.104 , ≤ 6.12.* (semver) Unaffected: 6.18.45 , ≤ 6.18.* (semver) Unaffected: 7.1.9 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/ip_vs.h",
            "net/netfilter/ipvs/ip_vs_core.c",
            "net/netfilter/ipvs/ip_vs_xmit.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3b8f79af0e98f27b932b0b416e9c52b692d31ff9",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "3c779b258c9c3c3567af68d4f45c2f751f35bd0e",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "be65fa324640c7a95e30b146159a2be5cc73f22e",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "a69a4b3fff5814d079beff9a1e9d369994b2ed47",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "243d0187ec4c3837b9b0004f18d1068e46115760",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "646922a0379496154e8c8faca4f8e2fd9100cacc",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/net/ip_vs.h",
            "net/netfilter/ipvs/ip_vs_core.c",
            "net/netfilter/ipvs/ip_vs_xmit.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.12"
            },
            {
              "lessThan": "2.6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.152",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.183",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.152",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.104",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.45",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.9",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipvs: avoid out-of-bounds write in ip_vs_nat_icmp\n\nSashiko warns that local attacker can modify the packet\nwhile it is processed by IPVS. Some places read the\nIP ihl field multiple times which can cause out-of-bounds\naccess. One such place is ip_vs_nat_icmp where we\ncan write after the validated area.\n\nFix it by providing ciph argument just like it is done for\nIPv6 and use ciph-\u003elen as offset to the embedded transport\nheader.\n\nModify some IPv4 header checks by reading the ihl field\nonly once."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The OOB write in ip_vs_nat_icmp() requires a local process to change the embedded IPv4 ihl in skb frags between ip_vs_fill_iph_skb_icmp() validation and the NAT write; remote-only ICMP to IPVS netfilter hooks cannot perform that TOCTOU without local access to the packet buffer.\nAC:L - A local attacker controls both sides of the race by concurrently injecting ICMP errors with TCP/UDP/SCTP payloads matching an IPVS NAT connection and modifying the embedded header ihl in skb frags during softirq processing; no victim-specific state or uncontrollable heap layout is required.\nPR:L - Triggering requires a local account able to race skb frag modification (e.g., via raw/packet sockets with CAP_NET_RAW, obtainable in a user namespace) against IPVS ICMP NAT handling on a host where IPVS is already configured; no init-namespace root is needed.\nUI:N - No victim user interaction is required; exploitation is driven entirely by attacker-controlled local packet injection and concurrent frag modification while IPVS processes ICMP errors on NAT-mode connections through LOCAL_IN, LOCAL_OUT, or FORWARD hooks.\nS:U - The out-of-bounds write corrupts kernel skb memory on the IPVS load-balancer host within the same kernel security authority; it does not cross VM, container, or IOMMU boundaries into a separate security scope.\nC:H - Writing TCP/UDP/SCTP port fields and running ip_send_check() using a re-read inflated ihl corrupts skb data beyond the validated region; out-of-bounds kernel memory corruption is exploitable for information disclosure and heap layout control.\nI:H - The bug is an out-of-bounds write of 16-bit port values (and checksum updates over an attacker-inflated header length) past skb_ensure_writable()\u0027s bound, enabling adjacent kernel memory corruption and potential control-flow hijacking on internet-facing IPVS NAT nodes.\nA:H - Corrupting skb header memory beyond the ensured writable area can cause kernel oops or panic during ICMP NAT mangling; a local attacker can repeatedly trigger the race on kube-proxy IPVS nodes and hardware load balancers running IPVS NAT mode."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-25T05:42:04.705Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/3b8f79af0e98f27b932b0b416e9c52b692d31ff9"
        },
        {
          "url": "https://git.kernel.org/stable/c/3c779b258c9c3c3567af68d4f45c2f751f35bd0e"
        },
        {
          "url": "https://git.kernel.org/stable/c/be65fa324640c7a95e30b146159a2be5cc73f22e"
        },
        {
          "url": "https://git.kernel.org/stable/c/a69a4b3fff5814d079beff9a1e9d369994b2ed47"
        },
        {
          "url": "https://git.kernel.org/stable/c/243d0187ec4c3837b9b0004f18d1068e46115760"
        },
        {
          "url": "https://git.kernel.org/stable/c/646922a0379496154e8c8faca4f8e2fd9100cacc"
        }
      ],
      "title": "ipvs: avoid out-of-bounds write in ip_vs_nat_icmp",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74724",
    "datePublished": "2026-08-22T15:33:15.832Z",
    "dateReserved": "2026-08-15T05:44:03.929Z",
    "dateUpdated": "2026-08-25T05:42:04.705Z",
    "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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.