VulnerabilityPublished 25 Sep 2026Updated 30 Oct 2026

CVE-2026-97559: Linux kernel · smb: client: fail DACL rewrite when the new DACL exceeds 64K

Source GCVE Database

Compare

Authoritative record:CVE-2026-97559· Medium

Not known to be exploited · fixed in f033d6e5aadf3e8c6a12873110557ed40cd71388 : update Linux kernel when convenient.

Data as of 30 Oct 2026, 17:33 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in f033d6e5aadf3e8c6a12873110557ed40cd71388, ee13d687d06a6fbb2008625dd560c654231b28e0, d05045177a855386bca5e1909e08d06290e6e3b3 +3

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-34vg-4qp7-6958

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ f5065508897a922327f32223082325d10b069ebc, < f033d6e5aadf3e8c6a12873110557ed40cd71388	Fixed in f033d6e5aadf3e8c6a12873110557ed40cd71388
LinuxLinux	Affected ≥ f5065508897a922327f32223082325d10b069ebc, < ee13d687d06a6fbb2008625dd560c654231b28e0	Fixed in ee13d687d06a6fbb2008625dd560c654231b28e0
LinuxLinux	Affected ≥ f5065508897a922327f32223082325d10b069ebc, < d05045177a855386bca5e1909e08d06290e6e3b3	Fixed in d05045177a855386bca5e1909e08d06290e6e3b3
LinuxLinux	Affected ≥ f5065508897a922327f32223082325d10b069ebc, < d433376abc47e10870ae732f89c7c1a60b199a0c	Fixed in d433376abc47e10870ae732f89c7c1a60b199a0c
LinuxLinux	Affected ≥ f5065508897a922327f32223082325d10b069ebc, < 284877c6189fda1ac3d81771dd8482660a0c7dc1	Fixed in 284877c6189fda1ac3d81771dd8482660a0c7dc1
LinuxLinux	Affected ≥ f5065508897a922327f32223082325d10b069ebc, < 2ef532a01f44687f5b95001e88247cf05bff9892	Fixed in 2ef532a01f44687f5b95001e88247cf05bff9892

AI-suggested

The vulnerability has been fixed by modifying the Linux kernel SMB client code to use a 32-bit accumulator for DACL size and to refuse operations that would cause the DACL to exceed the 64K byte limit. Users should apply the official Linux kernel updates that include this fix to prevent this issue.

Description

A vulnerability in the Linux kernel SMB client causes failure when rewriting a DACL if the new DACL exceeds 64K in size. The issue arises from using a 16-bit accumulator for DACL size, which can wrap around and corrupt the DACL data sent to the server. The flaw is fixed by switching to a 32-bit accumulator and refusing operations that would overflow the 64K limit.

Impact

The vulnerability causes corruption of the DACL data sent to the SMB server when the new DACL size exceeds 64K bytes. This corruption could lead to improper access control information being transmitted, potentially affecting SMB client-server interactions. However, the issue does not cause out-of-bounds writes or memory corruption beyond the allocated buffer. There is no evidence of exploitation in the wild.

References

Community reviews

Loading reviews…