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CVE-2026-63994

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.
Lifecycle PUBLISHED1 preserved revisionFact urn:baitaphish:canonical-cve-fact-revision:v2:cab86a19e5f48469e12b2758b487641ca592f322199b56ccf0a253adde56b107
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
1

Preserved source conflicts

No provider value was silently selected as the winner.

affected · 2 assertions

{"defaultStatus":"affected","product":"Linux","programFiles":["net/ipv4/ip_tunnel_core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.9"},{"lessThan":"5.9","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.259","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.210","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.176","versionType":"semver"},{"lessT…

  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/affected/1

{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/ipv4/ip_tunnel_core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"95b6d772bfe788331d9742d73eaa12e113b2adc4","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"},{"lessThan":"7254aef4d1a7e18e887af9010e2f2dc34806789b","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"},{"lessThan":"bf8b3f34c37c162357138e7c0942723b8b94fed1","status":"affected","version":"4cb47a8644cc9eb8ec81…

  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/affected/0

Affected products and versions

2 source assertions
{"defaultStatus":"affected","product":"Linux","programFiles":["net/ipv4/ip_tunnel_core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.9"},{"lessThan":"5.9","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.259","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.210","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.176","versionType":"semver"},{"lessT…
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/affected/1
{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/ipv4/ip_tunnel_core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"95b6d772bfe788331d9742d73eaa12e113b2adc4","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"},{"lessThan":"7254aef4d1a7e18e887af9010e2f2dc34806789b","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"},{"lessThan":"bf8b3f34c37c162357138e7c0942723b8b94fed1","status":"affected","version":"4cb47a8644cc9eb8ec81…
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/affected/0

Provider-owned CVSS observations

1 source assertion
{"metric":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"metric_type":"cvssV3_1"}
  • cve_program_cvelist_v5cvss
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/metrics/0/cvssV3_1

Source references

8 source assertions
{"url":"https://git.kernel.org/stable/c/50750d86a2e5266aba0c295483b3397843198b11"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/references/4
{"url":"https://git.kernel.org/stable/c/6dff77899b9e9fe5d854abda3a98ad04e7229ef7"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/references/5
{"url":"https://git.kernel.org/stable/c/7254aef4d1a7e18e887af9010e2f2dc34806789b"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/references/1
{"url":"https://git.kernel.org/stable/c/76cd9398a0470257ab765bdf5f358a2af2e17934"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/references/3
{"url":"https://git.kernel.org/stable/c/95b6d772bfe788331d9742d73eaa12e113b2adc4"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/references/0
{"url":"https://git.kernel.org/stable/c/b4bc94353050b1fa7b702bd4c6600710dd926cff"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/references/7
{"url":"https://git.kernel.org/stable/c/bf8b3f34c37c162357138e7c0942723b8b94fed1"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/references/2
{"url":"https://git.kernel.org/stable/c/f3f204541f280a6ecb04503a0d6794d93990ca43"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:4ff2d53c0623018ee6deb6abf86a89b04770b8b4ad4e1b66687d0f022194ec4e · sha256:98a05fe47e3943a8… · /containers/cna/references/6

Attribution and limitations

  • CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →

Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.

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