CVE-2026-43112: Linux kernel · fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath
Source GCVE Database
Not known to be exploited · CVSS 8.8 High · fixed in fbced33599653471b4581dfe1abc7b467031f126 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in fbced33599653471b4581dfe1abc7b467031f126, a2ba20c17de8eb028f96b1d85f119d3d25655bd9, 86f9c23e0814cfdffda9eedf0c591c51ba209010 +5
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 May 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.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- access.redhat.com/errata/RHSA-2026:62637 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62638 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62639 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62640 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62641 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62642 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65839 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65851 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34911 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36018 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36365 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36366 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath When cifs_sanitize_prepath is called with an empty string or a string containing only delimiters (e.g., "/"), the current logic attempts to check *(cursor2 - 1) before cursor2 has advanced. This results in an out-of-bounds read. This patch adds an early exit check after stripping prepended delimiters. If no path content remains, the function returns NULL. The bug was identified via manual audit and verified using a standalone test case compiled with AddressSanitizer, which triggered a SEGV on affected inputs.
References
- nvd.nist.gov/vuln/detail/CVE-2026-43112 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62637 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62638 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62639 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62640 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62641 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62642 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65839 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65851 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-43112 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2467015 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)
- git.kernel.org/stable/c/2d29214448ec0f4e7e18bb1c14dd4a6c07f1c439 (opens in a new tab)
- git.kernel.org/stable/c/49b1ce6d7cfb6c5a49f68bf5ccfcfb6ba14e63c3 (opens in a new tab)
- git.kernel.org/stable/c/5d4fe469fe7dbff7d874c196bb680a82f2625d95 (opens in a new tab)
- git.kernel.org/stable/c/78ec5bf2f589ec7fd8f169394bfeca541b077317 (opens in a new tab)
- git.kernel.org/stable/c/86f9c23e0814cfdffda9eedf0c591c51ba209010 (opens in a new tab)
- git.kernel.org/stable/c/a2ba20c17de8eb028f96b1d85f119d3d25655bd9 (opens in a new tab)
- git.kernel.org/stable/c/fbced33599653471b4581dfe1abc7b467031f126 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43112.json (opens in a new tab)