CVE-2025-39975: Linux kernel · smb: client: fix wrong index reference in smb2_compound_op()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 6.17.0-1006.6 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.17.0-1006.6, 6.17.0-1003.3, 6.17.0-6.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade Linux kernel to 6.17.0-1006.6, 6.17.0-1003.3 or 6.17.0-6.6.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| linux-hwe-edge | Affected
| Fixed in
|
AI-suggested
A fix for this vulnerability has been implemented in the Linux kernel. Users and administrators should apply the official kernel updates that include the corrected smb2_compound_op() function to remediate this issue. Since no vendor advisory or patch links are provided, check the official Linux kernel repositories or vendor advisories for the relevant patch and update instructions.
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.
References
- nvd.nist.gov/vuln/detail/CVE-2025-39975 (opens in a new tab)
- git.kernel.org/stable/c/093615fc76063ea08d454ba86677ce64c736e806 (opens in a new tab)
- git.kernel.org/stable/c/ba7bcfd52c66dd1c2dfa5142aca7e4a70b62dfa5 (opens in a new tab)
- git.kernel.org/stable/c/bfb1e2aad1fecef8320fd71332acde0d53a8d699 (opens in a new tab)
- git.kernel.org/stable/c/fbe2dc6a9c7318f7263f5e4d50f6272b931c5756 (opens in a new tab)
- ubuntu.com/security/CVE-2025-39975 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-39975 (opens in a new tab)
- git.kernel.org/linus/fbe2dc6a9c7318f7263f5e4d50f6272b931c5756 (opens in a new tab)