Critical severity9.8NVD Advisory· Published Jul 19, 2026· Updated Jul 30, 2026
CVE-2026-63994
CVE-2026-63994
Description
In the Linux kernel, the following vulnerability has been resolved:
tunnels: load network headers after skb_cow() in iptunnel_pmtud_build_icmp[v6]()
Sashiko found that iptunnel_pmtud_build_icmp() and iptunnel_pmtud_build_icmpv6() were caching ip_hdr() and ipv6_hdr() before an skb_cow() call which can reallocate skb->head.
Fix this possible UAF by initializing the local variables after the skb_cow() call.
Remove skb_reset_network_header() calls which were not needed.
Affected products
15- osv-coords14 versionspkg:linux/kernelpkg:rpm/opensuse/dtb-aarch64&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-64kb&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-azure&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-default&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-default-base&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-build&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-source&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-syms&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/kernel-zfcpdump&distro=openSUSE%20Leap%2016.0
>= 5.9.0, < 5.10.259+ 13 more
- (no CPE)range: >= 5.9.0, < 5.10.259
- (no CPE)range: < 6.12.0-160000.37.1
- (no CPE)range: < 6.12.0-160000.37.1
- (no CPE)range: < 6.12.0-160000.37.1
- (no CPE)range: < 6.12.0-160000.37.1
- (no CPE)range: < 6.12.0-160000.37.1.160000.2.19
- (no CPE)range: < 6.12.0-160000.37.1
- (no CPE)range: < 6.12.0-160000.37.1
- (no CPE)range: < 6.12.0-160000.37.1
- (no CPE)range: < 6.12.0-160000.37.1
- (no CPE)range: < 6.12.0-160000.37.1
- (no CPE)range: < 6.12.0-160000.37.1
- (no CPE)range: < 6.12.0-160000.37.1
- (no CPE)range: < 6.12.0-160000.37.1
Patches
Vulnerability mechanics
References
8- git.kernel.org/stable/c/50750d86a2e5266aba0c295483b3397843198b11nvd
- git.kernel.org/stable/c/6dff77899b9e9fe5d854abda3a98ad04e7229ef7nvd
- git.kernel.org/stable/c/7254aef4d1a7e18e887af9010e2f2dc34806789bnvd
- git.kernel.org/stable/c/76cd9398a0470257ab765bdf5f358a2af2e17934nvd
- git.kernel.org/stable/c/95b6d772bfe788331d9742d73eaa12e113b2adc4nvd
- git.kernel.org/stable/c/b4bc94353050b1fa7b702bd4c6600710dd926cffnvd
- git.kernel.org/stable/c/bf8b3f34c37c162357138e7c0942723b8b94fed1nvd
- git.kernel.org/stable/c/f3f204541f280a6ecb04503a0d6794d93990ca43nvd
News mentions
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