CVE-2025-21946: linux Out-of-bounds Read
CVSS: 8.8v3.1HighModified
AliasesUBUNTU-CVE-2025-21946DEBIAN-CVE-2025-21946
Published 01-04-2025Last modified 05-08-2026
Vulnerability summary
CVE-2025-21946 is a high (CVSS 8.8) Out-of-bounds Read vulnerability in linux. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 40.9% of scored vulnerabilities.
CVSS score
8.8/10
010
High · v3.1 (CVE.org)EPSS score
0.49%
0%100%
Low · +0.01 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.
- 05-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix out-of-bounds in parse_sec_desc() If osidoffset, gsidoffset and dacloffset could be greater than smb_ntsd struct size. If it is smaller, It could cause slab-out-of-bounds. And when validating sid, It need to check it included subauth array size.
CVSS metrics
5 scores · 4 sources · 2 versionsHigh 8.8Preferred score · OSV · Ubuntu (Ecosystem advisory) · calculated from vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:NSourcesSingle source
High 8.8Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HSources4 sources · 7.1–8.8
- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HDiffers
- NVDNIST7.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HDiffers
EPSS trend
Probability
0.49%
Chance of exploitation in the next 30 days
Percentile
41%
Versus all other CVEs
30-day change
+0.01 pp
From 0.48% on 19-09-2026
19-09-202619-10-2026
EPSS score0.49%
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, < f4ee19528664777af8b842f8f001be98345aa973 | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < c1569dbbe2d43041be9f3fef7ca08bec3b66ad1b | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < 159d059cbcb0e6d0e7a7b34af3862ba09a6b22d1 | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < 6a9831180d0b23b5c97e2bd841aefc8f82900172 | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < d6e13e19063db24f94b690159d0633aaf72a0f03 | 5.15
- linux_kernel≥ 5.15, < 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< 6.1.162-1 | < 6.12.19-1
3 vendors · 129 products
