Answer in brief
CVE-2025-21768 records a Unknown severity vulnerability in net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=6c8702c60b88651072460f3f4026c7dfe2521d12 <e2ef3fa31353b30bda94358fe5205c141289746d || >=6c8702c60b88651072460f3f4026c7dfe2521d12 <5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a || >=6c8702c60b88651072460f3f4026c7dfe2521d12 <4c0f200c7d06fedddde82209c099014d63f4a6c0 || >=6c8702c60b88651072460f3f4026c7dfe2521d12 <92191dd1073088753821b862b791dcc83e558e07 | e2ef3fa31353b30bda94358fe5205c141289746d, 5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a, 4c0f200c7d06fedddde82209c099014d63f4a6c0, 92191dd1073088753821b862b791dcc83e558e07 |
| Linux/Linuxgeneric | 4.10 | Not reported |
Published upstream
Feb 27, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 21, 2026
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.
Quoted source text, attributed separately from HOL analysis.