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CriticalFix available

xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full The depth check in xfrm6_input_addr() is off by one: if (1 + sp->len == XFRM_MAX_DEPTH) goto drop; ... sp->xvec[sp->len++] = x; xfrm_input() can leave sp->len == XFRM_MAX_DEPTH, and the transport-mode receive path re-enters IPv6 input via xfrm_trans_reinject() with that secpath preserved. If the inner packet carries a destination-options HAO option or a type-2 routing header, xfrm6_input_addr() is called with sp->len == XFRM_MAX_DEPTH; the check (1 + 6 == 6) is false, so sp->xvec[sp->len++] writes one slot past the 6-element xvec[]. The write stays within the sec_path allocation (invisible to KASAN); UBSAN_BOUNDS flags it and panics under panic_on_warn. Use "sp->len >= XFRM_MAX_DEPTH", matching xfrm_input(). This also restores one chain level the old check rejected at sp->len == 5. UBSAN: array-index-out-of-bounds in net/ipv6/xfrm6_input.c:309:10 index 6 is out of range for type 'xfrm_state *[6]'

Products
Kernel
Affected versions
Not specified
Fixed versions
5.10.270, 5.15.221, 6.1.188, 6.12.110, 6.18.52, 6.6.157, 7.2.6
CVEs
CVE-2026-89783
Confirmed fixed CVEs
Not specified
Updated in this feed
7 Nov 2026, 16:35 UTC · Revision 1

Source evidence

xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full

core-osv · Original source

Published 16 Sept 2026, 08:48 UTC

In the Linux kernel, the following vulnerability has been resolved: xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full The depth check in xfrm6_input_addr() is off by one: if (1 + sp->len == XFRM_MAX_DEPTH) goto drop; ... sp->xvec[sp->len++] = x; xfrm_input() can leave sp->len == XFRM_MAX_DEPTH, and the transport-mode receive path re-enters IPv6 input via xfrm_trans_reinject() with that secpath preserved. If the inner packet carries a destination-options HAO option or a type-2 routing header, xfrm6_input_addr() is called with sp->len == XFRM_MAX_DEPTH; the check (1 + 6 == 6) is false, so sp->xvec[sp->len++] writes one slot past the 6-element xvec[]. The write stays within the sec_path allocation (invisible to KASAN); UBSAN_BOUNDS flags it and panics under panic_on_warn. Use "sp->len >= XFRM_MAX_DEPTH", matching xfrm_input(). This also restores one chain level the old check rejected at sp->len == 5. UBSAN: array-index-out-of-bounds in net/ipv6/xfrm6_input.c:309:10 index 6 is out of range for type 'xfrm_state *[6]'

osv:CVE-2026-89783

Kernel

Fixed versions: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6

Complete source record
{
  "id": "4b46ccffabae049032b24b26c9bb9535420fd7068d3048d4480b9f0e8a9dfb95",
  "url": "https://osv.dev/vulnerability/CVE-2026-89783",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full The depth check in xfrm6_input_addr() is off by one: if (1 + sp->len == XFRM_MAX_DEPTH) goto drop; ... sp->xvec[sp->len++] = x; xfrm_input() can leave sp->len == XFRM_MAX_DEPTH, and the transport-mode receive path re-enters IPv6 input via xfrm_trans_reinject() with that secpath preserved. If the inner packet carries a destination-options HAO option or a type-2 routing header, xfrm6_input_addr() is called with sp->len == XFRM_MAX_DEPTH; the check (1 + 6 == 6) is false, so sp->xvec[sp->len++] writes one slot past the 6-element xvec[]. The write stays within the sec_path allocation (invisible to KASAN); UBSAN_BOUNDS flags it and panics under panic_on_warn. Use \"sp->len >= XFRM_MAX_DEPTH\", matching xfrm_input(). This also restores one chain level the old check rejected at sp->len == 5. UBSAN: array-index-out-of-bounds in net/ipv6/xfrm6_input.c:309:10 index 6 is out of range for type 'xfrm_state *[6]'",
    "evidence": "osv:CVE-2026-89783",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.270",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.221",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.188",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.157",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.110",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.52",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.6",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-89783",
      "aliases": [
        "CVE-2026-89783"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "9473e1f631de339c50bde1e3bd09e1045fe90fd5"
                },
                {
                  "fixed": "91fc387f63c00ddfb5221127a17bac97549a8343"
                },
                {
                  "fixed": "68e8737fe8e72f085c608cff322b3d2de8340af1"
                },
                {
                  "fixed": "8fe2c53fb81f5ad5be43af2ad09583f7c78b4b77"
                },
                {
                  "fixed": "bdcda866c89f9a8b1acdabf02d26cde9fbe501d8"
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                {
                  "fixed": "48996649222e95008cdb98cd58579e3fc8e5ee06"
                },
                {
                  "fixed": "0f679e0523ddfff3fb554336ceb874b0e51e9cd3"
                },
                {
                  "fixed": "5f35a29a5eed3d80befd32050843ac88dea3d61a"
                },
                {
                  "fixed": "5d9e3bf34fec9a5d237e4b7cef4a707bc2e091bc"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89783.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "2.6.25"
                },
                {
                  "fixed": "5.10.270"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
                },
                {
                  "fixed": "5.15.221"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "6.1.188"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.157"
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              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.110"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.52"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.6"
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              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89783.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:51.020954834Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0f679e0523ddfff3fb554336ceb874b0e51e9cd3",
        "https://git.kernel.org/stable/c/48996649222e95008cdb98cd58579e3fc8e5ee06",
        "https://git.kernel.org/stable/c/5d9e3bf34fec9a5d237e4b7cef4a707bc2e091bc",
        "https://git.kernel.org/stable/c/5f35a29a5eed3d80befd32050843ac88dea3d61a",
        "https://git.kernel.org/stable/c/68e8737fe8e72f085c608cff322b3d2de8340af1",
        "https://git.kernel.org/stable/c/8fe2c53fb81f5ad5be43af2ad09583f7c78b4b77",
        "https://git.kernel.org/stable/c/91fc387f63c00ddfb5221127a17bac97549a8343",
        "https://git.kernel.org/stable/c/bdcda866c89f9a8b1acdabf02d26cde9fbe501d8",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89783.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-89783",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89783.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-89783",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 519887,
  "published_at": "2026-09-16T08:48:21.761+00:00"
}