9.8

CVE-2025-39975: smb: client: fix wrong index reference in smb2_compound_op()

Deferred
AliasesUBUNTU-CVE-2025-39975DEBIAN-CVE-2025-39975
Published 15-10-2025Last modified 05-08-2026

Vulnerability summary

CVE-2025-39975 is a critical (CVSS 9.8) vulnerability in linux. EPSS estimates a 0.47% chance of exploitation in the next 30 days, higher than 40.4% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.8 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.47%
0%100%
Low · 0.00 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 2
MGASA-2025-0309MGASA-2025-0310

Timeline

  1. 15-10-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix wrong index reference in smb2_compound_op() In smb2_compound_op(), the loop that processes each command's response uses wrong indices when accessing response bufferes. This incorrect indexing leads to improper handling of command results. Also, if incorrectly computed index is greather than or equal to MAX_COMPOUND, it can cause out-of-bounds accesses.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.47%

Chance of exploitation in the next 30 days

Percentile

40%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.47% 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

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu98 products
  • linux< 6.17.0-6.6
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.17.0-1003.3
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.12.57-1 | < 6.16.10-1
Linux1 product
  • linux≥ 5ddcc9e92d54548219985ce4de88618fb53e14ec, < ba7bcfd52c66dd1c2dfa5142aca7e4a70b62dfa5 | ≥ efe8db3ecaa40a8520dc9a54283dcecd82ceea9c, < bfb1e2aad1fecef8320fd71332acde0d53a8d699 | ≥ 3681c74d342db75b0d641ba60de27bf73e16e66b, < 093615fc76063ea08d454ba86677ce64c736e806 | ≥ 3681c74d342db75b0d641ba60de27bf73e16e66b, < fbe2dc6a9c7318f7263f5e4d50f6272b931c5756 | 77aefd1d9b790f60634adebbdcfffbe934f41c34 | ≥ 6.6.75, < 6.6.109 | ≥ 6.12.12, < 6.12.50 | ≥ 6.13.1, < 6.14 | 6.14

3 vendors · 100 products

References

8 links