CVE-2025-21759ipv6: mcast: extend RCU protection in igmp6_send()
- 7.8HighCVSS base score
- 7.8%Exploitation in 30 daysEPSS · top 5.3% 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: mcast: extend RCU protection in igmp6_send() igmp6_send() can be called without RTNL or RCU being held. Extend RCU protection so that we can safely fetch the net pointer and avoid a potential UAF. Note that we no longer can use sock_alloc_send_skb() because ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep. Instead use alloc_skb() and charge the net->ipv6.igmp_sk socket under RCU protection.
Timeline
ID reserved
By Linux
- 2 months later
· 2 months later
Published
- 19 months later
· 19 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 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CISA-ADPADP (enrichment) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 7.8% · top 5.3% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 – < 638e8fe3563a82f298fe537a28d5342a97278cf1
- affected b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 – < 6901bbb169e3add6c037218d996790cef6b3d650
- affected b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 – < 7e0a818ecc4d62e7fb668ea02de0bfe8ba0b7dff
- affected b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 – < 81b25a07ebf53f9ef4ca8f3d96a8ddb94561dd5a
- affected b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 – < 0bf8e2f3768629d437a32cb824149e6e98254381
- affected b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 – < 8e92d6a413feaf968a33f0b439ecf27404407458
- affected b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 – < 087c1faa594fa07a66933d750c0b2610aa1a2946
- affected 2.6.26
- unaffected < 2.6.26
- unaffected 5.10.271 – ≤ 5.10.*
- unaffected 5.15.222 – ≤ 5.15.*
- unaffected 6.1.189 – ≤ 6.1.*
- unaffected 6.6.79 – ≤ 6.6.*
- unaffected 6.12.16 – ≤ 6.12.*
- unaffected 6.13.4 – ≤ 6.13.*
- unaffected 6.14 – ≤ *
References
References7
- https://git.kernel.org/stable/c/638e8fe3563a82f298fe537a28d5342a97278cf1 (opens in a new tab)
- https://git.kernel.org/stable/c/6901bbb169e3add6c037218d996790cef6b3d650 (opens in a new tab)
- https://git.kernel.org/stable/c/7e0a818ecc4d62e7fb668ea02de0bfe8ba0b7dff (opens in a new tab)
- https://git.kernel.org/stable/c/81b25a07ebf53f9ef4ca8f3d96a8ddb94561dd5a (opens in a new tab)
- https://git.kernel.org/stable/c/0bf8e2f3768629d437a32cb824149e6e98254381 (opens in a new tab)
- https://git.kernel.org/stable/c/8e92d6a413feaf968a33f0b439ecf27404407458 (opens in a new tab)
- https://git.kernel.org/stable/c/087c1faa594fa07a66933d750c0b2610aa1a2946 (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-2025-5157 (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-2025-21759)Record last updated .