5.5

CVE-2025-21846: acct: perform last write from workqueue

Modified
AliasesUBUNTU-CVE-2025-21846DEBIAN-CVE-2025-21846
Published 12-03-2025Last modified 15-10-2026

Vulnerability summary

CVE-2025-21846 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 16.7% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.25%
0%100%
Low · +0.01 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 56 · Related 50
DLA-4178-1DLA-4193-1DSA-5900-1MGASA-2025-0111MGASA-2025-0112RHSA-2025:20095

Timeline

  1. 12-03-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: acct: perform last write from workqueue In [1] it was reported that the acct(2) system call can be used to trigger NULL deref in cases where it is set to write to a file that triggers an internal lookup. This can e.g., happen when pointing acc(2) to /sys/power/resume. At the point the where the write to this file happens the calling task has already exited and called exit_fs(). A lookup will thus trigger a NULL-deref when accessing current->fs. Reorganize the code so that the the final write happens from the workqueue but with the caller's credentials. This preserves the (strange) permission model and has almost no regression risk. This api should stop to exist though.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.25%

Chance of exploitation in the next 30 days

Percentile

17%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.24% 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.

Ubuntu137 products
  • linuxAll versions (No fix recorded) | < 5.4.0-216.236 | < 5.15.0-140.150 | < 6.8.0-78.78
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.4.0-1146.156 | < 5.15.0-1084.91 | < 6.8.0-1035.37
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 8acbf4a88c6a98c8ed00afd1a7d1abcca9b4735e | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < b03782ae707cc45e65242c7cddd8e28f1c22cde5 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 5d5b936cfa4b0d5670ca7420ef165a074bc008eb | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 5ee8da9bea70dda492d61f075658939af33d8410 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 5c928e14a2ccd99462f2351ead627b58075bb736 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 5a59ced8ffc71973d42c82484a719c8f6ac8f7f7 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < a8136afca090412a36429cb6c2543c714d9c0f84 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 56d5f3eba3f5de0efdd556de4ef381e109b973a9 | 2.6.12
  • linux_kernel≥ 2.6.12, < 6.1.130 | ≥ 6.2, < 6.6.80 | ≥ 6.7, < 6.12.17 | ≥ 6.13, < 6.13.5 | 6.14:rc1 | 6.14:rc2 | 6.14:rc3
Debian1 product
  • linux< 6.1.133-1 | < 6.12.17-1

3 vendors · 140 products

References

58 links
Show all 58 references