CVE-2026-31668 (GCVE-0-2026-31668)
Vulnerability from cvelistv5
Published
2026-04-24 14:45
Modified
2026-04-27 14:04
Severity ?
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: seg6: separate dst_cache for input and output paths in seg6 lwtunnel The seg6 lwtunnel uses a single dst_cache per encap route, shared between seg6_input_core() and seg6_output_core(). These two paths can perform the post-encap SID lookup in different routing contexts (e.g., ip rules matching on the ingress interface, or VRF table separation). Whichever path runs first populates the cache, and the other reuses it blindly, bypassing its own lookup. Fix this by splitting the cache into cache_input and cache_output, so each path maintains its own cached dst independently.
References
Impacted products
Vendor Product Version
Linux Linux Version: 6c8702c60b88651072460f3f4026c7dfe2521d12
Version: 6c8702c60b88651072460f3f4026c7dfe2521d12
Version: 6c8702c60b88651072460f3f4026c7dfe2521d12
Version: 6c8702c60b88651072460f3f4026c7dfe2521d12
Version: 6c8702c60b88651072460f3f4026c7dfe2521d12
Version: 6c8702c60b88651072460f3f4026c7dfe2521d12
Version: 6c8702c60b88651072460f3f4026c7dfe2521d12
Version: 6c8702c60b88651072460f3f4026c7dfe2521d12
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/seg6_iptunnel.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1dec91d3b1cefb82635761b7812154af3ef46449",
              "status": "affected",
              "version": "6c8702c60b88651072460f3f4026c7dfe2521d12",
              "versionType": "git"
            },
            {
              "lessThan": "750569d6987a0ff46317a4b86eb3907e296287bf",
              "status": "affected",
              "version": "6c8702c60b88651072460f3f4026c7dfe2521d12",
              "versionType": "git"
            },
            {
              "lessThan": "57d0374d14fa667dec6952173b93e7e84486d5c9",
              "status": "affected",
              "version": "6c8702c60b88651072460f3f4026c7dfe2521d12",
              "versionType": "git"
            },
            {
              "lessThan": "84d458018b147176b259347103fccb7e93abd2b1",
              "status": "affected",
              "version": "6c8702c60b88651072460f3f4026c7dfe2521d12",
              "versionType": "git"
            },
            {
              "lessThan": "6305ad032b03d2ea4181b953a66e19a9a6ed053c",
              "status": "affected",
              "version": "6c8702c60b88651072460f3f4026c7dfe2521d12",
              "versionType": "git"
            },
            {
              "lessThan": "fb56de5d99218de49d5d43ef3a99e062ecd0f9a1",
              "status": "affected",
              "version": "6c8702c60b88651072460f3f4026c7dfe2521d12",
              "versionType": "git"
            },
            {
              "lessThan": "17d87d42874f5d6c1a0ccc6d9190dfe82a9a7a6a",
              "status": "affected",
              "version": "6c8702c60b88651072460f3f4026c7dfe2521d12",
              "versionType": "git"
            },
            {
              "lessThan": "c3812651b522fe8437ebb7063b75ddb95b571643",
              "status": "affected",
              "version": "6c8702c60b88651072460f3f4026c7dfe2521d12",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/seg6_iptunnel.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.10"
            },
            {
              "lessThan": "4.10",
              "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": "6.1.169",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.135",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.82",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.23",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.13",
              "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": "4.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.203",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.169",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.135",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.82",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.23",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.13",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nseg6: separate dst_cache for input and output paths in seg6 lwtunnel\n\nThe seg6 lwtunnel uses a single dst_cache per encap route, shared\nbetween seg6_input_core() and seg6_output_core(). These two paths\ncan perform the post-encap SID lookup in different routing contexts\n(e.g., ip rules matching on the ingress interface, or VRF table\nseparation). Whichever path runs first populates the cache, and the\nother reuses it blindly, bypassing its own lookup.\n\nFix this by splitting the cache into cache_input and cache_output,\nso each path maintains its own cached dst independently."
        }
      ],
      "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": "2026-04-27T14:04:52.464Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/1dec91d3b1cefb82635761b7812154af3ef46449"
        },
        {
          "url": "https://git.kernel.org/stable/c/750569d6987a0ff46317a4b86eb3907e296287bf"
        },
        {
          "url": "https://git.kernel.org/stable/c/57d0374d14fa667dec6952173b93e7e84486d5c9"
        },
        {
          "url": "https://git.kernel.org/stable/c/84d458018b147176b259347103fccb7e93abd2b1"
        },
        {
          "url": "https://git.kernel.org/stable/c/6305ad032b03d2ea4181b953a66e19a9a6ed053c"
        },
        {
          "url": "https://git.kernel.org/stable/c/fb56de5d99218de49d5d43ef3a99e062ecd0f9a1"
        },
        {
          "url": "https://git.kernel.org/stable/c/17d87d42874f5d6c1a0ccc6d9190dfe82a9a7a6a"
        },
        {
          "url": "https://git.kernel.org/stable/c/c3812651b522fe8437ebb7063b75ddb95b571643"
        }
      ],
      "title": "seg6: separate dst_cache for input and output paths in seg6 lwtunnel",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31668",
    "datePublished": "2026-04-24T14:45:16.630Z",
    "dateReserved": "2026-03-09T15:48:24.129Z",
    "dateUpdated": "2026-04-27T14:04:52.464Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.