Vulnerability-Lookup

FKIE_CVE-2026-43186

Vulnerability from fkie_nvd - Published: 2026-05-06 12:16 - Updated: 2026-05-11 20:40

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: ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data() On the receive path, __ioam6_fill_trace_data() uses trace->nodelen to decide how much data to write for each node. It trusts this field as-is from the incoming packet, with no consistency check against trace->type (the 24-bit field that tells which data items are present). A crafted packet can set nodelen=0 while setting type bits 0-21, causing the function to write ~100 bytes past the allocated region (into skb_shared_info), which corrupts adjacent heap memory and leads to a kernel panic. Add a shared helper ioam6_trace_compute_nodelen() in ioam6.c to derive the expected nodelen from the type field, and use it: - in ioam6_iptunnel.c (send path, existing validation) to replace the open-coded computation; - in exthdrs.c (receive path, ipv6_hop_ioam) to drop packets whose nodelen is inconsistent with the type field, before any data is written. Per RFC 9197, bits 12-21 are each short (4-octet) fields, so they are included in IOAM6_MASK_SHORT_FIELDS (changed from 0xff100000 to 0xff1ffc00).

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0591d6509c2ff13f09ea2998434aba0c0472e978	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/632d233cf2e64a46865ae2c064ae3c9df7c8864f	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/6db8b56eed62baacaf37486e83378a72635c04cc	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/e90346a2f1e8917d5760a44a1f61c44e3b36d96b	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ea3632aefc04205436868541638e26f4a74d5637	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/f4d9d4b8fd839719d564651671e24c62c545c23b	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/fb3c662fafebc5b9d74417ed1de8759f6bb72143	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*

JSON

To clipboard

{
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    {
      "nodes": [
        {
          "cpeMatch": [
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  "descriptions": [
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      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()\n\nOn the receive path, __ioam6_fill_trace_data() uses trace-\u003enodelen\nto decide how much data to write for each node. It trusts this field\nas-is from the incoming packet, with no consistency check against\ntrace-\u003etype (the 24-bit field that tells which data items are\npresent). A crafted packet can set nodelen=0 while setting type bits\n0-21, causing the function to write ~100 bytes past the allocated\nregion (into skb_shared_info), which corrupts adjacent heap memory\nand leads to a kernel panic.\n\nAdd a shared helper ioam6_trace_compute_nodelen() in ioam6.c to\nderive the expected nodelen from the type field, and use it:\n\n  - in ioam6_iptunnel.c (send path, existing validation) to replace\n    the open-coded computation;\n  - in exthdrs.c (receive path, ipv6_hop_ioam) to drop packets whose\n    nodelen is inconsistent with the type field, before any data is\n    written.\n\nPer RFC 9197, bits 12-21 are each short (4-octet) fields, so they\nare included in IOAM6_MASK_SHORT_FIELDS (changed from 0xff100000 to\n0xff1ffc00)."
    }
  ],
  "id": "CVE-2026-43186",
  "lastModified": "2026-05-11T20:40:56.187",
  "metrics": {
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          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
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        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
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  "published": "2026-05-06T12:16:37.300",
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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    },
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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    }
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  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-43186 (GCVE-0-2026-43186)

Vulnerability from cvelistv5 – Published: 2026-05-06 11:27 – Updated: 2026-05-11 22:19

Title

ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()

Summary

Severity ?

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

7 references

URL	Tags
https://git.kernel.org/stable/c/f4d9d4b8fd839719d…
https://git.kernel.org/stable/c/fb3c662fafebc5b9d…
https://git.kernel.org/stable/c/632d233cf2e64a468…
https://git.kernel.org/stable/c/0591d6509c2ff13f0…
https://git.kernel.org/stable/c/e90346a2f1e8917d5…
https://git.kernel.org/stable/c/ea3632aefc0420543…
https://git.kernel.org/stable/c/6db8b56eed62baaca…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 , < f4d9d4b8fd839719d564651671e24c62c545c23b (git) Affected: 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 , < fb3c662fafebc5b9d74417ed1de8759f6bb72143 (git) Affected: 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 , < 632d233cf2e64a46865ae2c064ae3c9df7c8864f (git) Affected: 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 , < 0591d6509c2ff13f09ea2998434aba0c0472e978 (git) Affected: 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 , < e90346a2f1e8917d5760a44a1f61c44e3b36d96b (git) Affected: 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 , < ea3632aefc04205436868541638e26f4a74d5637 (git) Affected: 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 , < 6db8b56eed62baacaf37486e83378a72635c04cc (git)
Linux	Linux	Affected: 5.15 Unaffected: 0 , < 5.15 (semver) Unaffected: 5.15.202 , ≤ 5.15.* (semver) Unaffected: 6.1.165 , ≤ 6.1.* (semver) Unaffected: 6.6.128 , ≤ 6.6.* (semver) Unaffected: 6.12.75 , ≤ 6.12.* (semver) Unaffected: 6.18.16 , ≤ 6.18.* (semver) Unaffected: 6.19.6 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/ioam6.h",
            "net/ipv6/exthdrs.c",
            "net/ipv6/ioam6.c",
            "net/ipv6/ioam6_iptunnel.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "versionType": "git"
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              "status": "unaffected",
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              "versionType": "semver"
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              "versionType": "semver"
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              "status": "unaffected",
              "version": "6.12.75",
              "versionType": "semver"
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              "status": "unaffected",
              "version": "6.18.16",
              "versionType": "semver"
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              "version": "7.0",
              "versionType": "original_commit_for_fix"
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        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()\n\nOn the receive path, __ioam6_fill_trace_data() uses trace-\u003enodelen\nto decide how much data to write for each node. It trusts this field\nas-is from the incoming packet, with no consistency check against\ntrace-\u003etype (the 24-bit field that tells which data items are\npresent). A crafted packet can set nodelen=0 while setting type bits\n0-21, causing the function to write ~100 bytes past the allocated\nregion (into skb_shared_info), which corrupts adjacent heap memory\nand leads to a kernel panic.\n\nAdd a shared helper ioam6_trace_compute_nodelen() in ioam6.c to\nderive the expected nodelen from the type field, and use it:\n\n  - in ioam6_iptunnel.c (send path, existing validation) to replace\n    the open-coded computation;\n  - in exthdrs.c (receive path, ipv6_hop_ioam) to drop packets whose\n    nodelen is inconsistent with the type field, before any data is\n    written.\n\nPer RFC 9197, bits 12-21 are each short (4-octet) fields, so they\nare included in IOAM6_MASK_SHORT_FIELDS (changed from 0xff100000 to\n0xff1ffc00)."
        }
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            "version": "3.1"
          }
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      "providerMetadata": {
        "dateUpdated": "2026-05-11T22:19:30.665Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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        },
        {
          "url": "https://git.kernel.org/stable/c/632d233cf2e64a46865ae2c064ae3c9df7c8864f"
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        },
        {
          "url": "https://git.kernel.org/stable/c/6db8b56eed62baacaf37486e83378a72635c04cc"
        }
      ],
      "title": "ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
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  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43186",
    "datePublished": "2026-05-06T11:27:57.053Z",
    "dateReserved": "2026-05-01T14:12:55.991Z",
    "dateUpdated": "2026-05-11T22:19:30.665Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Action not permitted

FKIE_CVE-2026-43186

CVE-2026-43186 (GCVE-0-2026-43186)

Tags

Sightings

Nomenclature