CVE-2025-21944: linux Improper Locking
CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2025-21944DEBIAN-CVE-2025-21944
Published 01-04-2025Last modified 11-05-2026
Vulnerability summary
CVE-2025-21944 is a medium (CVSS 5.5) Improper Locking vulnerability in linux. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 4% of scored vulnerabilities.
CVSS score
5.5/10
010
Medium · v3.1 (NVD)EPSS score
0.15%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 20 · Related 18Timeline
- 01-04-2025PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix bug on trap in smb2_lock If lock count is greater than 1, flags could be old value. It should be checked with flags of smb_lock, not flags. It will cause bug-on trap from locks_free_lock in error handling routine.
CVSS metrics
4 scores · 3 sources · 2 versionsHigh 7.1Preferred score · OSV · Ubuntu (Ecosystem advisory) · calculated from vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NSourcesSingle source
Medium 5.5Preferred score · NVD (NIST)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.15%
Chance of exploitation in the next 30 days
Percentile
4%
Versus all other CVEs
30-day change
0.00 pp
From 0.15% on 19-09-2026
19-09-202619-10-2026
EPSS score0.15%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu126 products
- linuxAll versions (No fix recorded) | < 6.8.0-84.84
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 6.8.0-1039.41
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < 11e0e74e14f1832a95092f2c98ed3b99f57797ee | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < 8994f0ce8259f812b4f4a681d8298c6ff682efaa | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < dbcd7fdd86f77529210fe8978154a81cd479844c | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < 2b70e3ac79eacbdf32571f7af48dd81cdd957ca8 | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < e26e2d2e15daf1ab33e0135caf2304a0cfa2744b | 5.15
- linux_kernel≥ 5.15, < 6.1.131 | ≥ 6.2, < 6.6.83 | ≥ 6.7, < 6.12.19 | ≥ 6.13, < 6.13.7 | 6.14:rc1 | 6.14:rc2 | 6.14:rc3 | 6.14:rc4 | 6.14:rc5
Debian1 product
- linux< 6.1.133-1 | < 6.12.19-1
3 vendors · 129 products
