CVE-2025-21768net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels
- 5.5MediumCVSS base score
- 0.25%Exploitation in 30 daysEPSS · top 83% 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: net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels Some lwtunnels have a dst cache for post-transformation dst. If the packet destination did not change we may end up recording a reference to the lwtunnel in its own cache, and the lwtunnel state will never be freed. Discovered by the ioam6.sh test, kmemleak was recently fixed to catch per-cpu memory leaks. I'm not sure if rpl and seg6 can actually hit this, but in principle I don't see why not.
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 |
|---|---|---|---|
| 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)
- 0.25% · top 83% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected 6c8702c60b88651072460f3f4026c7dfe2521d12 – < 26f0b472ae2a82920e38c7cf41583951046d586a
- affected 6c8702c60b88651072460f3f4026c7dfe2521d12 – < e2ef3fa31353b30bda94358fe5205c141289746d
- affected 6c8702c60b88651072460f3f4026c7dfe2521d12 – < 5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a
- affected 6c8702c60b88651072460f3f4026c7dfe2521d12 – < 4c0f200c7d06fedddde82209c099014d63f4a6c0
- affected 6c8702c60b88651072460f3f4026c7dfe2521d12 – < 92191dd1073088753821b862b791dcc83e558e07
- affected 4.10
- unaffected < 4.10
- unaffected 6.1.191 – ≤ 6.1.*
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.16 – ≤ 6.12.*
- unaffected 6.13.4 – ≤ 6.13.*
- unaffected 6.14 – ≤ *
References
References5
- https://git.kernel.org/stable/c/26f0b472ae2a82920e38c7cf41583951046d586a (opens in a new tab)
- https://git.kernel.org/stable/c/e2ef3fa31353b30bda94358fe5205c141289746d (opens in a new tab)
- https://git.kernel.org/stable/c/5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a (opens in a new tab)
- https://git.kernel.org/stable/c/4c0f200c7d06fedddde82209c099014d63f4a6c0 (opens in a new tab)
- https://git.kernel.org/stable/c/92191dd1073088753821b862b791dcc83e558e07 (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-2025-5155 (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-2025-21768)Record last updated .