5.5

CVE-2025-21768: linux

CVSS: 5.5v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2025-21768DEBIAN-CVE-2025-21768
Published 27-02-2025Last modified 11-05-2026
Open JSON

Vulnerability summary

CVE-2025-21768 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.21% chance of exploitation in the next 30 days, higher than 9.8% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.21%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 20 · Related 21
SUSE-SU-2025:01600-1SUSE-SU-2025:01614-1SUSE-SU-2025:01707-1SUSE-SU-2025:01919-1SUSE-SU-2025:01951-1SUSE-SU-2025:01964-1

Timeline

  1. 27-02-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.21%

Chance of exploitation in the next 30 days

Percentile

10%

Versus all other CVEs

30-day change

+0.01 pp

From 0.20% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.21%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu137 products
  • linuxAll versions (No fix recorded) | < 6.8.0-78.78
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1035.37
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 6c8702c60b88651072460f3f4026c7dfe2521d12, < 5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a | ≥ 6c8702c60b88651072460f3f4026c7dfe2521d12, < 4c0f200c7d06fedddde82209c099014d63f4a6c0 | ≥ 6c8702c60b88651072460f3f4026c7dfe2521d12, < 92191dd1073088753821b862b791dcc83e558e07 | 4.10
  • linux_kernel≥ 4.10, < 6.12.16 | ≥ 6.13, < 6.13.4 | 6.14:rc1
Debian1 product
  • linuxAll versions (No fix recorded) | < 6.12.16-1

3 vendors · 140 products

References

16 links
Show all 16 references