5.5

CVE-2025-21666: linux NULL Pointer Dereference

CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2025-21666DEBIAN-CVE-2025-21666
Published 31-01-2025Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2025-21666 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12.1% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.22%
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 33 · Related 29
DLA-4075-1DLA-4076-1DSA-5860-1RHSA-2025:6966SUSE-SU-2025:0499-1SUSE-SU-2025:0557-1

Timeline

  1. 31-01-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: vsock: prevent null-ptr-deref in vsock_*[has_data|has_space] Recent reports have shown how we sometimes call vsock_*_has_data() when a vsock socket has been de-assigned from a transport (see attached links), but we shouldn't. Previous commits should have solved the real problems, but we may have more in the future, so to avoid null-ptr-deref, we can return 0 (no space, no data available) but with a warning. This way the code should continue to run in a nearly consistent state and have a warning that allows us to debug future problems.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.22%

Chance of exploitation in the next 30 days

Percentile

12%

Versus all other CVEs

30-day change

0.00 pp

From 0.22% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.22%

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

Ubuntu124 products
  • linux< 5.15.0-135.146 | < 6.8.0-62.65
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 5.15.0-1080.87 | < 6.8.0-1030.32
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ c0cfa2d8a788fcf45df5bf4070ab2474c88d543a, < daeac89cdb03d30028186f5ff7dc26ec8fa843e7 | ≥ c0cfa2d8a788fcf45df5bf4070ab2474c88d543a, < 9e5fed46ccd2c34c5fa5a9c8825ce4823fdc853e | ≥ c0cfa2d8a788fcf45df5bf4070ab2474c88d543a, < b52e50dd4fabd12944172bd486a4f4853b7f74dd | ≥ c0cfa2d8a788fcf45df5bf4070ab2474c88d543a, < bc9c49341f9728c31fe248c5fbba32d2e81a092b | ≥ c0cfa2d8a788fcf45df5bf4070ab2474c88d543a, < c23d1d4f8efefb72258e9cedce29de10d057f8ca | ≥ c0cfa2d8a788fcf45df5bf4070ab2474c88d543a, < 91751e248256efc111e52e15115840c35d85abaf | 5.5
  • linux_kernel≥ 5.5, < 5.15.177 | ≥ 5.16, < 6.1.127 | ≥ 6.2, < 6.6.74 | ≥ 6.7, < 6.12.11 | 6.13:rc1 | 6.13:rc2 | 6.13:rc3 | 6.13:rc4 | 6.13:rc5 | 6.13:rc6 | 6.13:rc7
Debian1 product
  • linux< 6.1.128-1 | < 6.12.11-1

3 vendors · 127 products

References

35 links
Show all 35 references