- 9.1CriticalCVSS base score
- 0.51%Exploitation in 30 daysEPSS · top 56% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By Linux
Published
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
| NVDNVD · Modified | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.51% · top 56% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.1.
Affected products
- affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f – < 5a92cb45e34749865d03daf8d3500f77b5f6644c
- affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f – < c7b7ec3e69e673c0d6b57f74d21da50c485c598e
- affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f – < 7f4f7efe7f30edd29c4988de01728bf2398217e4
- affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f – < e917d0c69f01af2bb4fbea2b66d560a53b3ac7ec
- affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f – < a096b6e34f602950af9a2b0856cd93a5f4c276d7
- affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f – < 43368636c663cff6e59dde93cf4b8e43ac28eb93
- affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f – < cb549df9ce4ee15c9d5b19ddab12cf2128e4313c
- affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f – < 509323077ef79a26ba0c60bb556e45c12c398b2d
- affected 5.9
- unaffected < 5.9
- unaffected 5.10.259 – ≤ 5.10.*
- unaffected 5.15.210 – ≤ 5.15.*
- unaffected 6.1.176 – ≤ 6.1.*
- unaffected 6.6.143 – ≤ 6.6.*
- unaffected 6.12.93 – ≤ 6.12.*
- unaffected 6.18.35 – ≤ 6.18.*
- unaffected 7.0.12 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References8
- https://git.kernel.org/stable/c/5a92cb45e34749865d03daf8d3500f77b5f6644c (opens in a new tab)
- https://git.kernel.org/stable/c/c7b7ec3e69e673c0d6b57f74d21da50c485c598e (opens in a new tab)
- https://git.kernel.org/stable/c/7f4f7efe7f30edd29c4988de01728bf2398217e4 (opens in a new tab)
- https://git.kernel.org/stable/c/e917d0c69f01af2bb4fbea2b66d560a53b3ac7ec (opens in a new tab)
- https://git.kernel.org/stable/c/a096b6e34f602950af9a2b0856cd93a5f4c276d7 (opens in a new tab)
- https://git.kernel.org/stable/c/43368636c663cff6e59dde93cf4b8e43ac28eb93 (opens in a new tab)
- https://git.kernel.org/stable/c/cb549df9ce4ee15c9d5b19ddab12cf2128e4313c (opens in a new tab)
- https://git.kernel.org/stable/c/509323077ef79a26ba0c60bb556e45c12c398b2d (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-45565 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-63992)Record last updated .