CVE-2026-63992 (GCVE-0-2026-63992)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:56 – Updated: 2026-10-19 20:18
VLAI
Title
tunnels: do not assume transport header in iptunnel_pmtud_check_icmp()
Summary
In the Linux kernel, the following vulnerability has been resolved: tunnels: do not assume transport header in iptunnel_pmtud_check_icmp() In some cases, iptunnel_pmtud_check_icmp() can be called while skb transport header is not set. This triggers an out-of-bound access, because (typeof(skb->transport_header))~0U is 65535. Access the icmp header based on IPv4 network header, after making sure icmp->type is present in skb linear part. Note that iptunnel_pmtud_check_icmpv6()) is fine.
Severity
9.1 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-16 15:34 UTC
CWE
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6637 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < 5a92cb45e34749865d03daf8d3500f77b5f6644c (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < c7b7ec3e69e673c0d6b57f74d21da50c485c598e (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < 7f4f7efe7f30edd29c4988de01728bf2398217e4 (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < e917d0c69f01af2bb4fbea2b66d560a53b3ac7ec (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < a096b6e34f602950af9a2b0856cd93a5f4c276d7 (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < 43368636c663cff6e59dde93cf4b8e43ac28eb93 (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < cb549df9ce4ee15c9d5b19ddab12cf2128e4313c (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < 509323077ef79a26ba0c60bb556e45c12c398b2d (git)
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Linux Linux Affected: 5.9
Unaffected: 0 , < 5.9 (semver)
Unaffected: 5.10.259 , ≤ 5.10.* (semver)
Unaffected: 5.15.210 , ≤ 5.15.* (semver)
Unaffected: 6.1.176 , ≤ 6.1.* (semver)
Unaffected: 6.6.143 , ≤ 6.6.* (semver)
Unaffected: 6.12.93 , ≤ 6.12.* (semver)
Unaffected: 6.18.35 , ≤ 6.18.* (semver)
Unaffected: 7.0.12 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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      "title": "kernel: tunnels: do not assume transport header in iptunnel_pmtud_check_icmp()",
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      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/2026/cve-2026-63992.json",
      "version": "18"
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}



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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
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  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • 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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.