Critical severity9.1NVD Advisory· Published Jul 19, 2026· Updated Oct 7, 2026
CVE-2026-63992
CVE-2026-63992
Description
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected products
97(expand)+ 6 more
- (no CPE)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*range: >=5.9,<5.10.259
- cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*
- osv-coords90 versionspkg:rpm/almalinux/kernel-rt-debugpkg:rpm/almalinux/kernel-64k-develpkg:rpm/almalinux/kernel-cross-headerspkg:rpm/almalinux/kernel-uki-virt-addonspkg:rpm/almalinux/kernel-rt-corepkg:rpm/almalinux/kernel-rt-debug-corepkg:rpm/almalinux/kernel-rt-modulespkg:rpm/opensuse/kernel-zfcpdump&distro=openSUSE%20Leap%2016.0pkg:rpm/almalinux/kernel-debugpkg:rpm/almalinux/kernel-zfcpdump-modulespkg:rpm/almalinux/kernel-debug-modules-extrapkg:rpm/almalinux/kernel-64k-debug-devel-matchedpkg:rpm/almalinux/kernel-rt-debug-modulespkg:rpm/almalinux/kernel-rt-debug-modules-extrapkg:rpm/almalinux/kernel-rt-develpkg:rpm/almalinux/kernel-rt-modules-extrapkg:rpm/almalinux/bpftoolpkg:rpm/almalinux/kernelpkg:rpm/almalinux/kernel-abi-stablelistspkg:rpm/almalinux/kernel-corepkg:rpm/almalinux/kernel-zfcpdump-develpkg:rpm/almalinux/perfpkg:rpm/opensuse/kernel-azure&distro=openSUSE%20Leap%2016.0pkg:rpm/almalinux/kernel-toolspkg:rpm/almalinux/kernel-tools-libspkg:rpm/almalinux/kernel-tools-libs-develpkg:rpm/almalinux/kernel-zfcpdump-modules-extrapkg:rpm/opensuse/dtb-aarch64&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-64kb&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-default&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-docs&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-kvmsmall&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-obs-qa&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-rt&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-syms&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-obs-build&distro=openSUSE%20Leap%2016.0pkg:rpm/almalinux/kernel-develpkg:rpm/almalinux/kernel-docpkg:linux/kernelpkg:rpm/almalinux/kernel-headerspkg:rpm/opensuse/kernel-default-base&distro=openSUSE%20Leap%2016.0pkg:rpm/almalinux/kernel-debug-corepkg:rpm/almalinux/kernel-modules-extrapkg:rpm/opensuse/kernel-source&distro=openSUSE%20Leap%2016.0pkg:rpm/almalinux/kernel-64k-corepkg:rpm/almalinux/kernel-64k-debugpkg:rpm/almalinux/kernel-64k-debug-develpkg:rpm/almalinux/kernel-64k-devel-matchedpkg:rpm/almalinux/kernel-64k-modulespkg:rpm/almalinux/kernel-devel-matchedpkg:rpm/almalinux/kernel-rt-64k-debug-develpkg:rpm/almalinux/kernel-rt-64k-develpkg:rpm/almalinux/kernel-zfcpdump-devel-matchedpkg:rpm/almalinux/kernel-rtpkg:rpm/almalinux/kernel-rt-debug-develpkg:rpm/almalinux/kernel-debug-develpkg:rpm/almalinux/kernel-debug-modulespkg:rpm/almalinux/kernel-modulespkg:rpm/almalinux/kernel-zfcpdumppkg:rpm/almalinux/python3-perfpkg:rpm/almalinux/kernel-64kpkg:rpm/almalinux/kernel-64k-debug-corepkg:rpm/almalinux/kernel-64k-debug-modulespkg:rpm/almalinux/kernel-64k-debug-modules-corepkg:rpm/almalinux/kernel-64k-debug-modules-extrapkg:rpm/almalinux/kernel-64k-modules-corepkg:rpm/almalinux/kernel-64k-modules-extrapkg:rpm/almalinux/kernel-debug-devel-matchedpkg:rpm/almalinux/kernel-debug-modules-corepkg:rpm/almalinux/kernel-debug-uki-virtpkg:rpm/almalinux/kernel-modules-corepkg:rpm/almalinux/kernel-modules-extra-matchedpkg:rpm/almalinux/kernel-rt-64kpkg:rpm/almalinux/kernel-rt-64k-corepkg:rpm/almalinux/kernel-rt-64k-debugpkg:rpm/almalinux/kernel-rt-64k-debug-corepkg:rpm/almalinux/kernel-rt-64k-debug-modulespkg:rpm/almalinux/kernel-rt-64k-debug-modules-corepkg:rpm/almalinux/kernel-rt-64k-debug-modules-extrapkg:rpm/almalinux/kernel-rt-64k-modulespkg:rpm/almalinux/kernel-rt-64k-modules-corepkg:rpm/almalinux/kernel-rt-64k-modules-extrapkg:rpm/almalinux/kernel-rt-debug-modules-corepkg:rpm/almalinux/kernel-rt-modules-corepkg:rpm/almalinux/kernel-uki-virtpkg:rpm/almalinux/kernel-zfcpdump-modules-corepkg:rpm/almalinux/libperfpkg:rpm/almalinux/rtlapkg:rpm/almalinux/rvpkg:rpm/almalinux/kernel-zfcpdump-core
< 4.18.0-553.171.1.rt7.512.el8_10+ 89 more
- (no CPE)range: < 4.18.0-553.171.1.rt7.512.el8_10
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 4.18.0-553.171.1.rt7.512.el8_10
- (no CPE)range: < 4.18.0-553.171.1.rt7.512.el8_10
- (no CPE)range: < 4.18.0-553.171.1.rt7.512.el8_10
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 4.18.0-553.171.1.rt7.512.el8_10
- (no CPE)range: < 4.18.0-553.171.1.rt7.512.el8_10
- (no CPE)range: < 4.18.0-553.171.1.rt7.512.el8_10
- (no CPE)range: < 4.18.0-553.171.1.rt7.512.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: >= 5.9.0, < 5.10.259
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 6.12.0-160000.38.1.160000.2.22
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 6.12.0-160000.38.1
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 4.18.0-553.171.1.rt7.512.el8_10
- (no CPE)range: < 4.18.0-553.171.1.rt7.512.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 4.18.0-553.171.1.el8_10
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 6.12.0-211.63.1.el10_2
- (no CPE)range: < 4.18.0-553.171.1.el8_10
Patches
Vulnerability mechanics
References
8- git.kernel.org/stable/c/43368636c663cff6e59dde93cf4b8e43ac28eb93nvdPatch
- git.kernel.org/stable/c/509323077ef79a26ba0c60bb556e45c12c398b2dnvdPatch
- git.kernel.org/stable/c/5a92cb45e34749865d03daf8d3500f77b5f6644cnvdPatch
- git.kernel.org/stable/c/7f4f7efe7f30edd29c4988de01728bf2398217e4nvdPatch
- git.kernel.org/stable/c/a096b6e34f602950af9a2b0856cd93a5f4c276d7nvdPatch
- git.kernel.org/stable/c/c7b7ec3e69e673c0d6b57f74d21da50c485c598envdPatch
- git.kernel.org/stable/c/cb549df9ce4ee15c9d5b19ddab12cf2128e4313cnvdPatch
- git.kernel.org/stable/c/e917d0c69f01af2bb4fbea2b66d560a53b3ac7ecnvdPatch
News mentions
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