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

Vulnerability from cvelistv5 – Published: 2026-07-19 14:56 – Updated: 2026-08-05 12:37
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
Assigner
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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                "confidentialityImpact": "HIGH",
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      "product_status:known_affected": "246",
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      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: tunnels: do not assume transport header in iptunnel_pmtud_check_icmp()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63992.json",
      "version": "3"
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      "cve": "CVE-2026-63992",
      "id": "CVE-2026-63992",
      "initial_release_date": "2026-07-21T13:02:01Z",
      "product_status:first_fixed": "104",
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      "product_status:known_not_affected": "121",
      "product_status:recommended": "107",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-63992",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-63992.json",
      "version": "10"
    }
  }
}



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Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.


Related by attack behaviour

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.