CVE-2025-40256: linux

CVSS: UnknownDeferred
AliasesUBUNTU-CVE-2025-40256DEBIAN-CVE-2025-40256
Published 04-12-2025Last modified 11-05-2026
Open JSON

Vulnerability summary

CVE-2025-40256 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.21% chance of exploitation in the next 30 days, higher than 10.2% of scored vulnerabilities.

Overall risk
0/100
0100
Minimal · default modelHow is this calculated?
CVSS score
Not scored
010
No CVSS score recorded
EPSS score
0.21%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 25 · Related 25
OPENSUSE-SU-2026:20145-1SUSE-SU-2026:0263-1SUSE-SU-2026:0278-1SUSE-SU-2026:0281-1SUSE-SU-2026:0293-1SUSE-SU-2026:0315-1

Timeline

  1. 04-12-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: also call xfrm_state_delete_tunnel at destroy time for states that were never added In commit b441cf3f8c4b ("xfrm: delete x->tunnel as we delete x"), I missed the case where state creation fails between full initialization (->init_state has been called) and being inserted on the lists. In this situation, ->init_state has been called, so for IPcomp tunnels, the fallback tunnel has been created and added onto the lists, but the user state never gets added, because we fail before that. The user state doesn't go through __xfrm_state_delete, so we don't call xfrm_state_delete_tunnel for those states, and we end up leaking the FB tunnel. There are several codepaths affected by this: the add/update paths, in both net/key and xfrm, and the migrate code (xfrm_migrate, xfrm_state_migrate). A "proper" rollback of the init_state work would probably be doable in the add/update code, but for migrate it gets more complicated as multiple states may be involved. At some point, the new (not-inserted) state will be destroyed, so call xfrm_state_delete_tunnel during xfrm_state_gc_destroy. Most states will have their fallback tunnel cleaned up during __xfrm_state_delete, which solves the issue that b441cf3f8c4b (and other patches before it) aimed at. All states (including FB tunnels) will be removed from the lists once xfrm_state_fini has called flush_work(&xfrm_state_gc_work).

CVSS metrics

Risk metrics not yet published.

EPSS trend

Probability

0.21%

Chance of exploitation in the next 30 days

Percentile

10%

Versus all other CVEs

30-day change

0.00 pp

From 0.21% on 21-09-2026

21-09-202621-10-2026
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

No weakness data has been published for this record.

Affected systems

Ubuntu95 products
  • linux< 6.17.0-14.14
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.17.0-1007.7
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.17.10-1
Linux1 product
  • linux≥ 1b28a7fae0128fa140a7dccd995182ff6cd1c67b, < 57b72d74d4651dc19d046308a8304eb9abfe66ac | ≥ 4b2c17d0f9be8b58bb30468bc81a4b61c985b04e, < 1dad653643f28ccc89be93f9440b8804cded85b2 | ≥ 0da961fa46da1b37ef868d9b603bd202136f8f8e, < 64441724387b4ac92f67ef51caaaeffe99c950d1 | ≥ d0e0d1097118461463b76562c7ebaabaa5b90b13, < 763e5c351206c1e4d910db4a1159053f6263689c | ≥ dc3636912d41770466543623cb76e7b88fdb42c7, < f7d879c19d306512c2e260f37e8a3e5c85e37c50 | ≥ b441cf3f8c4b8576639d20c8eb4aa32917602ecd, < d6fe5c740c573af10943b8353992e1325cdb2715 | ≥ b441cf3f8c4b8576639d20c8eb4aa32917602ecd, < 10deb69864840ccf96b00ac2ab3a2055c0c04721 | 6.16

3 vendors · 97 products

References

16 links
Show all 16 references