CriticalFix available

net/ipv6: ioam6: prevent schema length wraparound in trace fill

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: net/ipv6: ioam6: prevent schema length wraparound in trace fill ioam6_fill_trace_data() stores the schema contribution to the trace length in a u8. With bit 22 enabled and the largest schema payload, sclen becomes 1 + 1020 / 4, wraps from 256 to 0, and bypasses the remaining-space check. __ioam6_fill_trace_data() then positions the write cursor without reserving the schema area but still copies the 4-byte schema header and the full schema payload, overrunning the trace buffer. Keep sclen in an unsigned int so the remaining-space check and the write cursor calculation both see the full schema length.

Products: Kernel
Affected versions: Not specified
Fixed versions: 5.15.210, 6.1.168, 6.12.81, 6.18.22, 6.19.12, 6.6.134
CVEs: CVE-2026-43341
Confirmed fixed CVEs: Not specified
Updated in this feed: 8 Nov 2026, 00:32 UTC · Revision 1

Source evidence

net/ipv6: ioam6: prevent schema length wraparound in trace fill

core-osv · Original source

Published 8 May 2026, 13:37 UTC

osv:CVE-2026-43341

Kernel

Fixed versions: 5.15.210, 6.1.168, 6.6.134, 6.12.81, 6.18.22, 6.19.12

Complete source record

{
  "id": "601d71e3817f6966d3ef51e68e3ee2d8eafee39778f9c60ab826350efc7d766f",
  "url": "https://osv.dev/vulnerability/CVE-2026-43341",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net/ipv6: ioam6: prevent schema length wraparound in trace fill",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net/ipv6: ioam6: prevent schema length wraparound in trace fill ioam6_fill_trace_data() stores the schema contribution to the trace length in a u8. With bit 22 enabled and the largest schema payload, sclen becomes 1 + 1020 / 4, wraps from 256 to 0, and bypasses the remaining-space check. __ioam6_fill_trace_data() then positions the write cursor without reserving the schema area but still copies the 4-byte schema header and the full schema payload, overrunning the trace buffer. Keep sclen in an unsigned int so the remaining-space check and the write cursor calculation both see the full schema length.",
    "evidence": "osv:CVE-2026-43341",
    "products": [
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        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
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        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.15.210",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.168",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.134",
            "evidence": "/affected/1/ranges"
          },
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            "evidence": "/affected/1/ranges"
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            "evidence": "/affected/1/ranges"
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          {
            "value": "6.19.12",
            "evidence": "/affected/1/ranges"
          }
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        "affected_versions": []
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    "severity": "critical",
    "structured": {
      "id": "CVE-2026-43341",
      "aliases": [
        "CVE-2026-43341"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
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      "affected": [
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                {
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                {
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                {
                  "fixed": "d6e1c9b02d85a4f1f4ba6d68e916d9b610a3ed7d"
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                  "fixed": "5e67ba9bb531e1ec6599a82a065dea9040b9ce50"
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        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
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                  "introduced": "5.15.0"
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                  "introduced": "6.2.0"
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            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
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                {
                  "fixed": "6.12.81"
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              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
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                {
                  "fixed": "6.18.22"
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            {
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                {
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
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      ],
      "modified": "2026-10-28T02:30:52.224673937Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/184d2e9db27c0f76226b5cad16fe29510a5d2280",
        "https://git.kernel.org/stable/c/5e67ba9bb531e1ec6599a82a065dea9040b9ce50",
        "https://git.kernel.org/stable/c/77695a69baca9b99d95fad09fc78c2318736604f",
        "https://git.kernel.org/stable/c/d1b041080086e91d3733a5438a8c51ad5d3d8e09",
        "https://git.kernel.org/stable/c/d3a1fb2ca323d7a4e10ab3afbfa25e6d8921e4f2",
        "https://git.kernel.org/stable/c/d6e1c9b02d85a4f1f4ba6d68e916d9b610a3ed7d",
        "https://git.kernel.org/stable/c/e96d48b37708d53cbdc47f6f60b0714fc4a5f596",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43341.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-43341",
        "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/2026/43xxx/CVE-2026-43341.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-43341",
        "evidence": "/id"
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    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 520996,
  "published_at": "2026-05-08T13:37:19.256+00:00"
}