VulnerabilityPublished 28 Oct 2026

CVE-2026-99115: Linux kernel · ksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION

Source GCVE Database

Authoritative record:CVE-2026-99115

Not known to be exploited · fixed in db2267b27c054a6c2151ff7fbb67927e784f31d6 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 14:15 UTC

Severity

Low

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

Patch: Available – fixed in db2267b27c054a6c2151ff7fbb67927e784f31d6, beba2ef6f66a71f20531ac70a1acb0b221e362e9, ab057f271ef60ff8163818badc3de75c480eca07

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-h75c-7wh7-p5vh

What to do

Upgrade Linux kernel to db2267b27c054a6c2151ff7fbb67927e784f31d6, beba2ef6f66a71f20531ac70a1acb0b221e362e9 or ab057f271ef60ff8163818badc3de75c480eca07.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < db2267b27c054a6c2151ff7fbb67927e784f31d6	Fixed in db2267b27c054a6c2151ff7fbb67927e784f31d6
LinuxLinux	Affected ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < beba2ef6f66a71f20531ac70a1acb0b221e362e9	Fixed in beba2ef6f66a71f20531ac70a1acb0b221e362e9
LinuxLinux	Affected ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < ab057f271ef60ff8163818badc3de75c480eca07	Fixed in ab057f271ef60ff8163818badc3de75c480eca07
LinuxLinux	Affected =5.15	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to correctly populate the FileSysIdentifier field in FS_POSIX_INFORMATION responses. Users should apply the official kernel updates that include this patch once available. Until then, no specific workaround is documented. Monitor vendor advisories for patch availability.

Description

A vulnerability in the Linux kernel's ksmbd component involves the FS_POSIX_INFORMATION structure where the FileSysIdentifier field is not properly assigned in smb2_get_info_filesystem(). This can cause residual data from previous responses to be leaked to clients during compound SMB2 requests. The issue arises because the response buffer is reused without clearing the FileSysIdentifier field, potentially exposing unintended data. The fix involves correctly reporting the file system ID as returned by statfs().

Impact

Clients receiving FS_POSIX_INFORMATION responses from ksmbd may receive unintended residual data in the FileSysIdentifier field during compound SMB2 requests. This constitutes an information disclosure vulnerability, potentially leaking kernel memory contents related to previous SMB2 responses. There is no indication of code execution or privilege escalation. No known exploits in the wild have been reported.

References

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