CVE-2026-68300 (GCVE-0-2026-68300)

Vulnerability from cvelistv5 – Published: 2026-08-10 12:02 – Updated: 2026-08-19 16:32
VLAI
Title
sctp: auth: verify auth requirement when auth_chunk is NULL
Summary
In the Linux kernel, the following vulnerability has been resolved: sctp: auth: verify auth requirement when auth_chunk is NULL sctp_auth_chunk_verify() returns true unconditionally when chunk->auth_chunk is NULL, silently skipping authentication. This is incorrect when: 1. skb_clone() failed in the BH receive path, leaving auth_chunk NULL. In sctp_endpoint_bh_rcv() asoc is NULL for new connections, so the early sctp_auth_recv_cid() check cannot catch this. 2. No AUTH chunk precedes COOKIE-ECHO, so skb_clone() is never called and auth_chunk remains NULL. Fix by checking sctp_auth_recv_cid() when auth_chunk is NULL: if authentication is required, return false to drop the chunk; otherwise continue normally.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: bbd0d59809f923ea2b540cbd781b32110e249f6e , < a129792b3aef15002746c13522781d92ed3522c3 (git)
Affected: bbd0d59809f923ea2b540cbd781b32110e249f6e , < 5a022ac51ad83b4ce6c898f4b9eefc65bd26b247 (git)
Affected: bbd0d59809f923ea2b540cbd781b32110e249f6e , < 6caf0e8590c0bf05a76b0d387726adf3a6f3725c (git)
Affected: bbd0d59809f923ea2b540cbd781b32110e249f6e , < ec2e157fc9678a9bc411305a25aec3fd337d7efb (git)
Affected: bbd0d59809f923ea2b540cbd781b32110e249f6e , < 28c5fdce9dd955d2baf5e28987819b6d7cfaf646 (git)
Affected: bbd0d59809f923ea2b540cbd781b32110e249f6e , < 18957373920caf5cdaf5cf32e5d1d7a99ca7700a (git)
Affected: bbd0d59809f923ea2b540cbd781b32110e249f6e , < 83f5031f2a6a49d696eb4cc0898345d12f9c6451 (git)
Affected: bbd0d59809f923ea2b540cbd781b32110e249f6e , < 8e04823c120b376ef7dab14b60ebf6823aa16c14 (git)
guessed Create a notification for this product.
Linux Linux Affected: 2.6.24
Unaffected: 0 , < 2.6.24 (semver)
Unaffected: 5.10.265 , ≤ 5.10.* (semver)
Unaffected: 5.15.216 , ≤ 5.15.* (semver)
Unaffected: 6.1.183 , ≤ 6.1.* (semver)
Unaffected: 6.6.148 , ≤ 6.6.* (semver)
Unaffected: 6.12.101 , ≤ 6.12.* (semver)
Unaffected: 6.18.42 , ≤ 6.18.* (semver)
Unaffected: 7.1.6 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sctp/sm_statefuns.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a129792b3aef15002746c13522781d92ed3522c3",
              "status": "affected",
              "version": "bbd0d59809f923ea2b540cbd781b32110e249f6e",
              "versionType": "git"
            },
            {
              "lessThan": "5a022ac51ad83b4ce6c898f4b9eefc65bd26b247",
              "status": "affected",
              "version": "bbd0d59809f923ea2b540cbd781b32110e249f6e",
              "versionType": "git"
            },
            {
              "lessThan": "6caf0e8590c0bf05a76b0d387726adf3a6f3725c",
              "status": "affected",
              "version": "bbd0d59809f923ea2b540cbd781b32110e249f6e",
              "versionType": "git"
            },
            {
              "lessThan": "ec2e157fc9678a9bc411305a25aec3fd337d7efb",
              "status": "affected",
              "version": "bbd0d59809f923ea2b540cbd781b32110e249f6e",
              "versionType": "git"
            },
            {
              "lessThan": "28c5fdce9dd955d2baf5e28987819b6d7cfaf646",
              "status": "affected",
              "version": "bbd0d59809f923ea2b540cbd781b32110e249f6e",
              "versionType": "git"
            },
            {
              "lessThan": "18957373920caf5cdaf5cf32e5d1d7a99ca7700a",
              "status": "affected",
              "version": "bbd0d59809f923ea2b540cbd781b32110e249f6e",
              "versionType": "git"
            },
            {
              "lessThan": "83f5031f2a6a49d696eb4cc0898345d12f9c6451",
              "status": "affected",
              "version": "bbd0d59809f923ea2b540cbd781b32110e249f6e",
              "versionType": "git"
            },
            {
              "lessThan": "8e04823c120b376ef7dab14b60ebf6823aa16c14",
              "status": "affected",
              "version": "bbd0d59809f923ea2b540cbd781b32110e249f6e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sctp/sm_statefuns.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.24"
            },
            {
              "lessThan": "2.6.24",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "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": "5.10.265",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.216",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.183",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.148",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.101",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.42",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: auth: verify auth requirement when auth_chunk is NULL\n\nsctp_auth_chunk_verify() returns true unconditionally when\nchunk-\u003eauth_chunk is NULL, silently skipping authentication.\nThis is incorrect when:\n\n1. skb_clone() failed in the BH receive path, leaving auth_chunk\n   NULL. In sctp_endpoint_bh_rcv() asoc is NULL for new\n   connections, so the early sctp_auth_recv_cid() check cannot\n   catch this.\n\n2. No AUTH chunk precedes COOKIE-ECHO, so skb_clone() is never\n   called and auth_chunk remains NULL.\n\nFix by checking sctp_auth_recv_cid() when auth_chunk is NULL:\nif authentication is required, return false to drop the chunk;\notherwise continue normally."
        }
      ],
      "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"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The vulnerable code is SCTP COOKIE-ECHO chunk processing in the kernel\u0027s SCTP state machine, reached directly from packets received on the network from any remote peer over an arbitrarily routed SCTP connection.\nAC:L - The attacker deterministically triggers the bypass by completing a normal INIT/INIT-ACK exchange with the AUTH extension advertised and then sending COOKIE-ECHO with no preceding AUTH chunk; no race, no memory-layout dependency, and every step is under the attacker\u0027s control.\nPR:N - This is the pre-authentication association-establishment path itself; the attacker needs no credentials, no shared SCTP-AUTH key, and no account, since the bug is precisely that the required authentication is skipped.\nUI:N - The listening SCTP endpoint processes the crafted COOKIE-ECHO automatically in the receive path; no action by any local user or administrator is needed.\nS:U - The bypass affects the SCTP association and the application relying on it within the same host security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - An unauthenticated peer is admitted as an apparently authenticated one, and because peer.auth_capable is set the SCTP_AUTH_NO_AUTH notification is suppressed so the application cannot detect it, giving the attacker full read access to all data the service sends on that association.\nI:H - The attacker can inject arbitrary SCTP data and control chunks into the service as a trusted, supposedly key-verified peer, and can use the dupcook restart path to update or replace an existing association\u0027s state without authentication.\nA:H - Authenticating COOKIE-ECHO is the RFC 4895 defense against unauthorized association restart; bypassing it lets an attacker reset/take over an established association, dropping its queued state and denying service to the legitimate peer, and lets unauthorized peers consume association and accept-queue resources on an endpoint meant to admit only key-holding peers."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-19T16:32:51.209Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/a129792b3aef15002746c13522781d92ed3522c3"
        },
        {
          "url": "https://git.kernel.org/stable/c/5a022ac51ad83b4ce6c898f4b9eefc65bd26b247"
        },
        {
          "url": "https://git.kernel.org/stable/c/6caf0e8590c0bf05a76b0d387726adf3a6f3725c"
        },
        {
          "url": "https://git.kernel.org/stable/c/ec2e157fc9678a9bc411305a25aec3fd337d7efb"
        },
        {
          "url": "https://git.kernel.org/stable/c/28c5fdce9dd955d2baf5e28987819b6d7cfaf646"
        },
        {
          "url": "https://git.kernel.org/stable/c/18957373920caf5cdaf5cf32e5d1d7a99ca7700a"
        },
        {
          "url": "https://git.kernel.org/stable/c/83f5031f2a6a49d696eb4cc0898345d12f9c6451"
        },
        {
          "url": "https://git.kernel.org/stable/c/8e04823c120b376ef7dab14b60ebf6823aa16c14"
        }
      ],
      "title": "sctp: auth: verify auth requirement when auth_chunk is NULL",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68300",
    "datePublished": "2026-08-10T12:02:34.168Z",
    "dateReserved": "2026-07-30T09:28:09.380Z",
    "dateUpdated": "2026-08-19T16:32:51.209Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-68300",
      "date": "2026-08-20",
      "epss": "0.00597",
      "percentile": "0.45974"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-68300\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-10T13:20:19.560\",\"lastModified\":\"2026-08-19T17:20:41.187\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nsctp: auth: verify auth requirement when auth_chunk is NULL\\n\\nsctp_auth_chunk_verify() returns true unconditionally when\\nchunk-\u003eauth_chunk is NULL, silently skipping authentication.\\nThis is incorrect when:\\n\\n1. skb_clone() failed in the BH receive path, leaving auth_chunk\\n   NULL. In sctp_endpoint_bh_rcv() asoc is NULL for new\\n   connections, so the early sctp_auth_recv_cid() check cannot\\n   catch this.\\n\\n2. No AUTH chunk precedes COOKIE-ECHO, so skb_clone() is never\\n   called and auth_chunk remains NULL.\\n\\nFix by checking sctp_auth_recv_cid() when auth_chunk is NULL:\\nif authentication is required, return false to drop the chunk;\\notherwise continue normally.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/sctp/sm_statefuns.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"bbd0d59809f923ea2b540cbd781b32110e249f6e\",\"lessThan\":\"a129792b3aef15002746c13522781d92ed3522c3\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"bbd0d59809f923ea2b540cbd781b32110e249f6e\",\"lessThan\":\"5a022ac51ad83b4ce6c898f4b9eefc65bd26b247\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"bbd0d59809f923ea2b540cbd781b32110e249f6e\",\"lessThan\":\"6caf0e8590c0bf05a76b0d387726adf3a6f3725c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"bbd0d59809f923ea2b540cbd781b32110e249f6e\",\"lessThan\":\"ec2e157fc9678a9bc411305a25aec3fd337d7efb\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"bbd0d59809f923ea2b540cbd781b32110e249f6e\",\"lessThan\":\"28c5fdce9dd955d2baf5e28987819b6d7cfaf646\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"bbd0d59809f923ea2b540cbd781b32110e249f6e\",\"lessThan\":\"18957373920caf5cdaf5cf32e5d1d7a99ca7700a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"bbd0d59809f923ea2b540cbd781b32110e249f6e\",\"lessThan\":\"83f5031f2a6a49d696eb4cc0898345d12f9c6451\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"bbd0d59809f923ea2b540cbd781b32110e249f6e\",\"lessThan\":\"8e04823c120b376ef7dab14b60ebf6823aa16c14\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/sctp/sm_statefuns.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.24\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.24\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.265\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.216\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.183\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.148\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.101\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.42\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.6\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":9.8,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/18957373920caf5cdaf5cf32e5d1d7a99ca7700a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/28c5fdce9dd955d2baf5e28987819b6d7cfaf646\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/5a022ac51ad83b4ce6c898f4b9eefc65bd26b247\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/6caf0e8590c0bf05a76b0d387726adf3a6f3725c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/83f5031f2a6a49d696eb4cc0898345d12f9c6451\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/8e04823c120b376ef7dab14b60ebf6823aa16c14\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a129792b3aef15002746c13522781d92ed3522c3\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ec2e157fc9678a9bc411305a25aec3fd337d7efb\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-13T23:13:14+00:00",
      "cve": "CVE-2026-68300",
      "id": "CVE-2026-68300",
      "initial_release_date": "2026-08-10T00:00:00+00:00",
      "product_status:known_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: sctp: auth: verify auth requirement when auth_chunk is NULL",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68300.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-08-14T23:44:54Z",
      "cve": "CVE-2026-68300",
      "id": "CVE-2026-68300",
      "initial_release_date": "2026-08-14T17:14:24Z",
      "product_status:known_affected": "296",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-68300",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-68300.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.