VulnerabilityPublished 28 Oct 2026

CVE-2026-99109: Linux kernel · smb: client: reject SetEA requests that do not fit the request buffer

Source GCVE Database

Authoritative record:CVE-2026-99109

Not known to be exploited : upgrade to 9efbd764ab80fa86d2258550877a74d78a25e855 or 4aa2c106aef4bf3dfd97c30842db0767b26e8428 soon.

Data as of 28 Oct 2026, 14:15 UTC

Severity

High

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

Patch: Available – fixed in 9efbd764ab80fa86d2258550877a74d78a25e855, 4aa2c106aef4bf3dfd97c30842db0767b26e8428

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 2026
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.

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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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-wh32-mmf9-9f7g

What to do

Upgrade Linux kernel to 9efbd764ab80fa86d2258550877a74d78a25e855 or 4aa2c106aef4bf3dfd97c30842db0767b26e8428.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 9efbd764ab80fa86d2258550877a74d78a25e855	Fixed in 9efbd764ab80fa86d2258550877a74d78a25e855
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 4aa2c106aef4bf3dfd97c30842db0767b26e8428	Fixed in 4aa2c106aef4bf3dfd97c30842db0767b26e8428
LinuxLinux	Affected =2.6.12	Fixed in–

AI-suggested

A fix is available that applies the length checks before copying the extended attribute value into the SMB request buffer and adjusts byte counters to prevent overflow. Users should update their Linux kernel to a version that includes this patch once it is released. Until then, avoid using SMB1 mounts or untrusted extended attribute values on affected systems.

Description

A vulnerability in the Linux kernel SMB client allows out-of-bounds memory writes when processing SetEA requests with extended attribute values that do not fit the request buffer. This occurs because the CIFSSMBSetEA() function copies the extended attribute value without properly checking buffer size limits before the copy operation, potentially leading to memory corruption.

References

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