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VulnerabilityPublished Updated

CVE-2026-97555: Linux kernel · smb: client: fix heap overflow in DACL owner/group rewrite

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 8.8 High · fixed in fb736ab4fb8c4fdb8b2f9ccd3a62e03d11549ca1 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in fb736ab4fb8c4fdb8b2f9ccd3a62e03d11549ca1, d5cea6766ae1868a51c7d17d77d065b4f55c587f, 7fa84c9ca690643f429ae2709584a47e74b572c9 +2
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: 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 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ bc3e9dd9d104ca1b75644eab87b38ce8a924aef4, < fb736ab4fb8c4fdb8b2f9ccd3a62e03d11549ca1
Fixed in
  • fb736ab4fb8c4fdb8b2f9ccd3a62e03d11549ca1
LinuxLinuxAffected
  • ≥ bc3e9dd9d104ca1b75644eab87b38ce8a924aef4, < d5cea6766ae1868a51c7d17d77d065b4f55c587f
Fixed in
  • d5cea6766ae1868a51c7d17d77d065b4f55c587f
LinuxLinuxAffected
  • ≥ bc3e9dd9d104ca1b75644eab87b38ce8a924aef4, < 7fa84c9ca690643f429ae2709584a47e74b572c9
Fixed in
  • 7fa84c9ca690643f429ae2709584a47e74b572c9
LinuxLinuxAffected
  • ≥ bc3e9dd9d104ca1b75644eab87b38ce8a924aef4, < 2a9aee9ef5622d58d8aafaa3263b3ffe70e2d9dd
Fixed in
  • 2a9aee9ef5622d58d8aafaa3263b3ffe70e2d9dd
LinuxLinuxAffected
  • ≥ bc3e9dd9d104ca1b75644eab87b38ce8a924aef4, < 0ee150794c75bcd0be0e24ff3394f433cbae18cc
Fixed in
  • 0ee150794c75bcd0be0e24ff3394f433cbae18cc
LinuxLinuxAffected
  • =5.12
Fixed in–

AI-suggested

A fix is available in Linux kernel versions that include the specified commits (fb736ab4fb8c4fdb8b2f9ccd3a62e03d11549ca1 and others). Users should update from version 5.12 to a patched kernel release containing these fixes. No other specific mitigations are indicated.

Description

A heap overflow vulnerability in the Linux kernel's SMB client was fixed. The flaw occurs during rewriting of DACL owner/group SIDs when longer replacement SIDs cause buffer overflow due to insufficient allocation size. This can lead to memory corruption. The issue affects Linux kernel version 5.12 and was resolved by allocating sufficient buffer space for worst-case SID sizes.

References

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