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CVE-2025-21765ipv6: use RCU protection in ip6_default_advmss()
- 8.1HighCVSS base score
- 0.61%Exploitation in 30 daysEPSS · top 50% 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: ipv6: use RCU protection in ip6_default_advmss() ip6_default_advmss() needs rcu protection to make sure the net structure it reads does not disappear.
Timeline
ID reserved
By Linux
- 2 months later
· 2 months later
Published
- 21 months later
· 21 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 | High8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.61% · top 50% of all CVEs (15 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.1.
Affected products
- affected 5578689a4e3c04f2d43ea39736fd3fa396d80c6e – < 78ad057472d8c76e0602402269222f9f9c698790
- affected 5578689a4e3c04f2d43ea39736fd3fa396d80c6e – < d02f30d220ef9511568a48dba8a9004c65f8d904
- affected 5578689a4e3c04f2d43ea39736fd3fa396d80c6e – < 28de355b63ad42309ed5a03ee7c436c90512265b
- affected 5578689a4e3c04f2d43ea39736fd3fa396d80c6e – < 84212387caadb211cd9dadd6fd5563bd37dc1f5e
- affected 5578689a4e3c04f2d43ea39736fd3fa396d80c6e – < 4176a68b0db8fc74ac14fcd00ba8231371051dc2
- affected 5578689a4e3c04f2d43ea39736fd3fa396d80c6e – < 713a40c892f40300d63691d9f85b2a23b48fe1e8
- affected 5578689a4e3c04f2d43ea39736fd3fa396d80c6e – < 550ed693f47370502a71b85382e7f9e6417300b8
- affected 5578689a4e3c04f2d43ea39736fd3fa396d80c6e – < 3c8ffcd248da34fc41e52a46e51505900115fc2a
- affected 2.6.26
- unaffected < 2.6.26
- unaffected 5.4.291 – ≤ 5.4.*
- unaffected 5.10.235 – ≤ 5.10.*
- unaffected 5.15.179 – ≤ 5.15.*
- unaffected 6.1.129 – ≤ 6.1.*
- unaffected 6.6.79 – ≤ 6.6.*
- unaffected 6.12.16 – ≤ 6.12.*
- unaffected 6.13.4 – ≤ 6.13.*
- unaffected 6.14 – ≤ *
References
References15
- https://git.kernel.org/stable/c/78ad057472d8c76e0602402269222f9f9c698790 (opens in a new tab)
- https://git.kernel.org/stable/c/d02f30d220ef9511568a48dba8a9004c65f8d904 (opens in a new tab)
- https://git.kernel.org/stable/c/28de355b63ad42309ed5a03ee7c436c90512265b (opens in a new tab)
- https://git.kernel.org/stable/c/84212387caadb211cd9dadd6fd5563bd37dc1f5e (opens in a new tab)
- https://git.kernel.org/stable/c/4176a68b0db8fc74ac14fcd00ba8231371051dc2 (opens in a new tab)
- https://git.kernel.org/stable/c/713a40c892f40300d63691d9f85b2a23b48fe1e8 (opens in a new tab)
- https://git.kernel.org/stable/c/550ed693f47370502a71b85382e7f9e6417300b8 (opens in a new tab)
- https://git.kernel.org/stable/c/3c8ffcd248da34fc41e52a46e51505900115fc2a (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html (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-2025-5164 (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-2025-21765)Record last updated .