CVE-2025-21768
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-401
- Record status
- Modified
Affected
- Linux Kernel < 6.12.16
- Linux Kernel < 6.13.4
- Linux Kernel 6.14
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-21768.md and follow it. Check whether this project is affected by CVE-2025-21768. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/4c0f200c7d06fedddde82209c099014d63f4a6c0
- https://git.kernel.org/stable/c/5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a
- https://git.kernel.org/stable/c/92191dd1073088753821b862b791dcc83e558e07
References
- https://git.kernel.org/stable/c/26f0b472ae2a82920e38c7cf41583951046d586a
- https://git.kernel.org/stable/c/4c0f200c7d06fedddde82209c099014d63f4a6c0
- https://git.kernel.org/stable/c/5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a
- https://git.kernel.org/stable/c/92191dd1073088753821b862b791dcc83e558e07
- https://git.kernel.org/stable/c/e2ef3fa31353b30bda94358fe5205c141289746d