9.4

CVE-2025-39943: linux Out-of-bounds Read

CVSS: 9.4v3.1CriticalModified
AliasesUBUNTU-CVE-2025-39943DEBIAN-CVE-2025-39943
Published 04-10-2025Last modified 05-08-2026
Open JSON

Vulnerability summary

CVE-2025-39943 is a critical (CVSS 9.4) Out-of-bounds Read vulnerability in linux. EPSS estimates a 0.26% chance of exploitation in the next 30 days, higher than 16.6% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.4/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.26%
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 28 · Related 24
DLA-4379-1DSA-6053-1MGASA-2025-0309MGASA-2025-0310USN-8033-1USN-8033-2

Timeline

  1. 04-10-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: smbdirect: validate data_offset and data_length field of smb_direct_data_transfer If data_offset and data_length of smb_direct_data_transfer struct are invalid, out of bounds issue could happen. This patch validate data_offset and data_length field in recv_done.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.26%

Chance of exploitation in the next 30 days

Percentile

17%

Versus all other CVEs

30-day change

0.00 pp

From 0.26% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.26%

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

Ubuntu136 products
  • linux< 5.15.0-170.180 | < 6.8.0-106.106
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 5.15.0-1100.107 | < 6.8.0-1050.53
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 2ea086e35c3d726a3bacd0a971c1f02a50e98206, < 773fddf976d282ef059c36c575ddb81567acd6bc | ≥ 2ea086e35c3d726a3bacd0a971c1f02a50e98206, < bdaab5c6538e250a9654127e688ecbbeb6f771d5 | ≥ 2ea086e35c3d726a3bacd0a971c1f02a50e98206, < eb0378dde086363046ed3d7db7f126fc3f76fd70 | ≥ 2ea086e35c3d726a3bacd0a971c1f02a50e98206, < 8be498fcbd5b07272f560b45981d4b9e5a2ad885 | ≥ 2ea086e35c3d726a3bacd0a971c1f02a50e98206, < 529b121b00a6ee3c88fb3c01b443b2b81f686d48 | ≥ 2ea086e35c3d726a3bacd0a971c1f02a50e98206, < 5282491fc49d5614ac6ddcd012e5743eecb6a67c | 5.15
  • linux_kernel≥ 5.15.1, < 5.15.194 | ≥ 5.16, < 6.1.154 | ≥ 6.2, < 6.6.108 | ≥ 6.7, < 6.12.49 | ≥ 6.13, < 6.16.9 | 5.15 | 5.15:rc7 | 6.17:rc1 | 6.17:rc2 | 6.17:rc3 | 6.17:rc4 | 6.17:rc5 | 6.17:rc6
Debian1 product
  • linux< 6.1.158-1 | < 6.12.57-1 | < 6.16.9-1

3 vendors · 139 products

References

34 links
Show all 34 references