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CVE

CVE-2026-63992

tunnels: do not assume transport header in iptunnel_pmtud_check_icmp()
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CVE

CVE-2026-63992

tunnels: do not assume transport header in iptunnel_pmtud_check_icmp()

In the Linux kernel, the following vulnerability has been resolved:

tunnels: do not assume transport header in iptunnelpmtudcheck_icmp()

In some cases, iptunnelpmtudcheck_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 iptunnelpmtudcheck_icmpv6()) is fine.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.1
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
C
H
U
0
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
C
H
U
-

Related Resources

No items found.

References

https://git.kernel.org/stable/c/43368636c663cff6e59dde93cf4b8e43ac28eb93, https://git.kernel.org/stable/c/509323077ef79a26ba0c60bb556e45c12c398b2d, https://git.kernel.org/stable/c/5a92cb45e34749865d03daf8d3500f77b5f6644c, https://git.kernel.org/stable/c/7f4f7efe7f30edd29c4988de01728bf2398217e4, https://git.kernel.org/stable/c/a096b6e34f602950af9a2b0856cd93a5f4c276d7, https://git.kernel.org/stable/c/c7b7ec3e69e673c0d6b57f74d21da50c485c598e, https://git.kernel.org/stable/c/cb549df9ce4ee15c9d5b19ddab12cf2128e4313c, https://git.kernel.org/stable/c/e917d0c69f01af2bb4fbea2b66d560a53b3ac7ec, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63992.json, https://nvd.nist.gov/vuln/detail/CVE-2026-63992, https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Severity

9.1

CVSS Score
0
10

Basic Information

Base CVSS
9.1
EPSS Probability
0.00514%
EPSS Percentile
0.41789%
Introduced Version
4cb47a8644cc9eb8ec81190a50e79e6530d0297f,5.9.0,5.11.0,5.16.0,6.2.0,6.7.0,6.13.0,6.19.0,0
Fix Available
509323077ef79a26ba0c60bb556e45c12c398b2d,5.10.259,5.15.210,6.1.176,6.6.143,6.12.93,6.18.35,7.0.12,6.1.176-1,6.12.94-1,7.0.0-28.28~24.04.1,7.0.0-1016.16~24.04.1,7.0.0-28.28.1~24.04.3,0:5.15.0-323.211.3.3.el8uek,0:6.12.0-206.104.3.3.el9uek,0:5.15.0-323.211.3.3.el9uek,0:6.12.0-206.104.3.3.el10uek,0:5.10.259-258.1043.amzn2,0:1.0-0.amzn2,0:5.15.210-148.245.amzn2,1:6.18.35-68.127.amzn2023,1:1.0-0.amzn2023,1:6.1.176-220.358.amzn2023,1:6.12.94-123.174.amzn2023

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