CVE-2026-68320 (GCVE-0-2026-68320)
Vulnerability from cvelistv5
Published
2026-08-10 12:02
Modified
2026-08-19 16:33
Summary
In the Linux kernel, the following vulnerability has been resolved: sctp: fix auth_chunk_list capacity check in sctp_auth_ep_add_chunkid sctp_auth_ep_add_chunkid() uses SCTP_NUM_CHUNK_TYPES (20) as the capacity limit for ep->auth_chunk_list, allowing it to hold up to 20 chunk entries (param_hdr.length up to 24). However, the copy destination asoc->c.auth_chunks in struct sctp_cookie is only SCTP_AUTH_MAX_CHUNKS (16) entries (20 bytes). When more than 16 chunks are added, sctp_association_init() memcpy overflows the destination by up to 4 bytes. Fix by using SCTP_AUTH_MAX_CHUNKS as the capacity limit, matching the destination capacity.
Impacted products
Vendor Product Version
Linux Linux Version: 1f485649f52929d9937b346a920a522a7363e202
Version: 1f485649f52929d9937b346a920a522a7363e202
Version: 1f485649f52929d9937b346a920a522a7363e202
Version: 1f485649f52929d9937b346a920a522a7363e202
Version: 1f485649f52929d9937b346a920a522a7363e202
Version: 1f485649f52929d9937b346a920a522a7363e202
Version: 1f485649f52929d9937b346a920a522a7363e202
Version: 1f485649f52929d9937b346a920a522a7363e202
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sctp/auth.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3d22a7da2e264f407c729f33a0a346ff76108bc6",
              "status": "affected",
              "version": "1f485649f52929d9937b346a920a522a7363e202",
              "versionType": "git"
            },
            {
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              "version": "1f485649f52929d9937b346a920a522a7363e202",
              "versionType": "git"
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              "status": "affected",
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              "versionType": "git"
            },
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              "status": "affected",
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              "versionType": "git"
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              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sctp/auth.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
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                {
                  "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",
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                  "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: fix auth_chunk_list capacity check in sctp_auth_ep_add_chunkid\n\nsctp_auth_ep_add_chunkid() uses SCTP_NUM_CHUNK_TYPES (20) as the\ncapacity limit for ep-\u003eauth_chunk_list, allowing it to hold up to\n20 chunk entries (param_hdr.length up to 24). However, the copy\ndestination asoc-\u003ec.auth_chunks in struct sctp_cookie is only\nSCTP_AUTH_MAX_CHUNKS (16) entries (20 bytes). When more than 16\nchunks are added, sctp_association_init() memcpy overflows the\ndestination by up to 4 bytes.\n\nFix by using SCTP_AUTH_MAX_CHUNKS as the capacity limit, matching\nthe destination capacity."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The overflow condition can only be created locally: an attacker must call setsockopt(SCTP_AUTH_SUPPORTED) and then setsockopt(SCTP_AUTH_CHUNK) more than 16 times on an SCTP socket they own. A remote peer can trigger the memcpy by connecting to such a socket, but cannot itself populate the oversized chunk list.\nAC:L - The sequence is fully deterministic and entirely under attacker control \u2014 enable AUTH, add 17-20 distinct chunk IDs, then create an association via connect() or accept(); no race, timing window, or memory-layout condition is involved.\nPR:L - Creating an IPPROTO_SCTP socket and issuing SCTP_AUTH_SUPPORTED/SCTP_AUTH_CHUNK setsockopts requires no capability; sctp_setsockopt_auth_supported() enables AUTH per-endpoint regardless of the net.sctp.auth_enable sysctl, so any unprivileged local user reaches the bug.\nUI:N - The attacker performs every step from their own process \u2014 socket setup, setsockopt calls, and association establishment \u2014 with no action required from any other user or administrator.\nS:U - The corruption and the over-read are confined to the kernel\u0027s own SCTP association object; no other security authority or privilege domain is crossed.\nC:L - sctp_make_init()/sctp_make_init_ack() copy ntohs(auth_chunks-\u003elength) bytes from the 20-byte field, emitting up to 4 bytes past it (the adjacent raw_addr_list_len) inside the CHUNKS parameter of INIT/INIT-ACK sent to the remote peer \u2014 a real but small, strictly bounded out-of-bounds read.\nI:H - sctp_association_init() writes up to 4 bytes of fully attacker-chosen data (the chunk-ID values) past the end of asoc-\u003ec.auth_chunks into the adjacent kernel struct field, an out-of-bounds write of controlled content into kernel memory.\nA:H - On CONFIG_FORTIFY_SOURCE kernels the memcpy is flagged as a field-spanning write and emits a WARN, which is fatal on the widely used panic_on_warn configurations, and the out-of-bounds write itself corrupts SCTP association state; the trigger is cheap and repeatable by any local user."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-19T16:33:10.661Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/3d22a7da2e264f407c729f33a0a346ff76108bc6"
        },
        {
          "url": "https://git.kernel.org/stable/c/6837c1c19a259518974cbc5a52017646e3906564"
        },
        {
          "url": "https://git.kernel.org/stable/c/54bb4c03fa17cdcb157c26c33e60a78cf32960f5"
        },
        {
          "url": "https://git.kernel.org/stable/c/5a365f1e423444c5da7eb689a8661633dad43e48"
        },
        {
          "url": "https://git.kernel.org/stable/c/886e28e14ab655012779016d251fef53d103aa12"
        },
        {
          "url": "https://git.kernel.org/stable/c/11092d79eb2b7c0068382f72fc2416d1786bb2e0"
        },
        {
          "url": "https://git.kernel.org/stable/c/b6ea3dda09eb4d5caf7bbc00f857688cf9e98255"
        },
        {
          "url": "https://git.kernel.org/stable/c/ff04b26794a16a8a879eb4fd2c02c2d6b03850e9"
        }
      ],
      "title": "sctp: fix auth_chunk_list capacity check in sctp_auth_ep_add_chunkid",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68320",
    "datePublished": "2026-08-10T12:02:55.144Z",
    "dateReserved": "2026-07-30T09:28:09.382Z",
    "dateUpdated": "2026-08-19T16:33:10.661Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
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