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VulnerabilityPublished

CVE-2026-99274: Linux kernel · smb: client: fix fiemap wild read on empty truncated response

Source GCVE Database

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Authoritative record:CVE-2026-99274· High

Not known to be exploited · fixed in f5baa17a0f316c235d61623ac8e8fb32c2b3c0cc : patch Linux kernel soon.

Data as of 7 Nov 2026, 16:17 UTC

Severity
High

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

Thin evidence

One scorer or none
Patch
Available – fixed in f5baa17a0f316c235d61623ac8e8fb32c2b3c0cc, 31f6dbb29fe17fa9595c7e8b19fd92915b03a4ca, 4a426ca5be7e3dedbe76575b967db04fbf01136f

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 7 Nov 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 7 Nov 2026.

What to do

Upgrade Linux kernel to f5baa17a0f316c235d61623ac8e8fb32c2b3c0cc, 31f6dbb29fe17fa9595c7e8b19fd92915b03a4ca or 4a426ca5be7e3dedbe76575b967db04fbf01136f.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 2f3ebaba13cebd8badfb9aed31c0cf3cc82eb4f4, < f5baa17a0f316c235d61623ac8e8fb32c2b3c0cc
Fixed in
  • f5baa17a0f316c235d61623ac8e8fb32c2b3c0cc
LinuxLinuxAffected
  • ≥ 2f3ebaba13cebd8badfb9aed31c0cf3cc82eb4f4, < 31f6dbb29fe17fa9595c7e8b19fd92915b03a4ca
Fixed in
  • 31f6dbb29fe17fa9595c7e8b19fd92915b03a4ca
LinuxLinuxAffected
  • ≥ 2f3ebaba13cebd8badfb9aed31c0cf3cc82eb4f4, < 4a426ca5be7e3dedbe76575b967db04fbf01136f
Fixed in
  • 4a426ca5be7e3dedbe76575b967db04fbf01136f
LinuxLinuxAffected
  • =5.2
Fixed in–
Debiandebian/linuxpkg:deb/debian/linuxOther threatsAffected
  • =5.2
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix has been implemented in the Linux kernel to reject empty truncated range blobs and add proper boundary checks to prevent wild reads and infinite loops. Users should apply the official kernel update that includes this patch. No additional mitigations are indicated.

Description

A vulnerability in the Linux kernel SMB client related to the fiemap ioctl handling allows a wild read from an empty truncated response from a malicious SMB2 server. The flaw occurs when the server returns a STATUS_BUFFER_OVERFLOW with an empty output, causing the client to read memory before a NULL pointer, potentially leading to a kernel oops (crash). The issue has been fixed by rejecting empty truncated range blobs and adding checks to prevent infinite loops or underflows.

References

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