CVE-2025-21768: Linux kernel · net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 30 Oct 2026, 14:18 UTC
Rated Medium by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or noneExploitation evidence
Disclosed: evidence found.
CVE published 27 Feb 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
AI-suggested
A fix has been implemented in the Linux kernel to resolve the destination reference loops in rpl, seg6, and ioam6 lwtunnels. Users should apply the official kernel updates that include this fix. No additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel's IPv6 implementation involving lwtunnels was fixed to prevent destination reference loops in rpl, seg6, and ioam6 lwtunnels. The issue caused the lwtunnel state to never be freed due to self-referencing in the destination cache when the packet destination did not change.
References
- git.kernel.org/stable/c/26f0b472ae2a82920e38c7cf41583951046d586a (opens in a new tab)
- git.kernel.org/stable/c/e2ef3fa31353b30bda94358fe5205c141289746d (opens in a new tab)
- git.kernel.org/stable/c/5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a (opens in a new tab)
- git.kernel.org/stable/c/4c0f200c7d06fedddde82209c099014d63f4a6c0 (opens in a new tab)
- git.kernel.org/stable/c/92191dd1073088753821b862b791dcc83e558e07 (opens in a new tab)