CVE-2026-63992
tunnels: do not assume transport header in iptunnel_pmtud_check_icmp()
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
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.
| Vendor | linux |
| Product | linux |
| Ecosystems | |
| Industries | Technology |
| Published | Jul 19, 2026 |
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Affected Versions
Linux / Linux
4cb47a8644cc9eb8ec81190a50e79e6530d0297f < 5a92cb45e34749865d03daf8d3500f77b5f6644c 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < c7b7ec3e69e673c0d6b57f74d21da50c485c598e 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < 7f4f7efe7f30edd29c4988de01728bf2398217e4 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < e917d0c69f01af2bb4fbea2b66d560a53b3ac7ec 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < a096b6e34f602950af9a2b0856cd93a5f4c276d7 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < 43368636c663cff6e59dde93cf4b8e43ac28eb93 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < cb549df9ce4ee15c9d5b19ddab12cf2128e4313c 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < 509323077ef79a26ba0c60bb556e45c12c398b2d
Linux / Linux
5.9
References
git.kernel.org: https://git.kernel.org/stable/c/5a92cb45e34749865d03daf8d3500f77b5f6644c git.kernel.org: https://git.kernel.org/stable/c/c7b7ec3e69e673c0d6b57f74d21da50c485c598e git.kernel.org: https://git.kernel.org/stable/c/7f4f7efe7f30edd29c4988de01728bf2398217e4 git.kernel.org: https://git.kernel.org/stable/c/e917d0c69f01af2bb4fbea2b66d560a53b3ac7ec git.kernel.org: https://git.kernel.org/stable/c/a096b6e34f602950af9a2b0856cd93a5f4c276d7 git.kernel.org: https://git.kernel.org/stable/c/43368636c663cff6e59dde93cf4b8e43ac28eb93 git.kernel.org: https://git.kernel.org/stable/c/cb549df9ce4ee15c9d5b19ddab12cf2128e4313c git.kernel.org: https://git.kernel.org/stable/c/509323077ef79a26ba0c60bb556e45c12c398b2d