7.8

CVE-2026-43091: xfrm: Wait for RCU readers during policy netns exit

Modified
AliasesUBUNTU-CVE-2026-43091DEBIAN-CVE-2026-43091
Published 06-05-2026Last modified 30-10-2026

Vulnerability summary

CVE-2026-43091 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.13%
0%100%
Low · -0.05 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 25 · Related 24
LSN-0122-1OPENSUSE-SU-2026:21555-1SUSE-SU-2026:23066-1SUSE-SU-2026:23068-1SUSE-SU-2026:23221-1SUSE-SU-2026:23231-1

Timeline

  1. 06-05-2026
    PublishedVulnerability first disclosed.
  2. 30-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: Wait for RCU readers during policy netns exit xfrm_policy_fini() frees the policy_bydst hash tables after flushing the policy work items and deleting all policies, but it does not wait for concurrent RCU readers to leave their read-side critical sections first. The policy_bydst tables are published via rcu_assign_pointer() and are looked up through rcu_dereference_check(), so netns teardown must also wait for an RCU grace period before freeing the table memory. Fix this by adding synchronize_rcu() before freeing the policy hash tables.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.13%

Chance of exploitation in the next 30 days

Percentile

3%

Versus all other CVEs

30-day change

Decrease -0.05 pp

From 0.18% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu156 products
  • linuxAll versions (No fix recorded) | < 6.8.0-136.136
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1061.64
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ e1e551bc56302b80ff930c966f9985095fb1b70d, < b2faee12538b5b008eaef65a4201eb29cb5cefb3 | ≥ e1e551bc56302b80ff930c966f9985095fb1b70d, < b66920a3348c0f63ba18365248fa21fbf0b3a937 | ≥ e1e551bc56302b80ff930c966f9985095fb1b70d, < 438b1f668ad58f46ce699bb48e4698a7839e3f9e | ≥ e1e551bc56302b80ff930c966f9985095fb1b70d, < 3733fce2871c9bca9dd18a1a23b1432ea215a094 | ≥ e1e551bc56302b80ff930c966f9985095fb1b70d, < 33a3149dd81a1e2f52b80ee1e0fc380b39f3d028 | ≥ e1e551bc56302b80ff930c966f9985095fb1b70d, < 069daad4f2ae9c5c108131995529d5f02392c446 | 4.9
  • linux_kernel≥ 4.9, < 6.6.136 | ≥ 6.7, < 6.12.83 | ≥ 6.13, < 6.18.24 | ≥ 6.19, < 6.19.14 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6 | 7.0:rc7
Debian1 product
  • linuxAll versions (No fix recorded) | < 6.12.85-1 | < 6.19.14-1

3 vendors · 159 products

References

24 links
Show all 24 references