CVE-2026-43215: Linux kernel · cifs: Fix locking usage for tcon fields
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 8.8 High · fixed in 953953abb66e52c224057ab91e404284fefeab62 : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:07 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in 953953abb66e52c224057ab91e404284fefeab62, 3969db6b22e3d90d8c5f22ac1a7fe0350a94c136, 601dd3b79769b38d30b693c40afdb2a4b7edf9d0 +2
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.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: cifs: Fix locking usage for tcon fields We used to use the cifs_tcp_ses_lock to protect a lot of objects that are not just the server, ses or tcon lists. We later introduced srv_lock, ses_lock and tc_lock to protect fields within the corresponding structs. This was done to provide a more granular protection and avoid unnecessary serialization. There were still a couple of uses of cifs_tcp_ses_lock to provide tcon fields. In this patch, I've replaced them with tc_lock.
References
- git.kernel.org/stable/c/953953abb66e52c224057ab91e404284fefeab62 (opens in a new tab)
- git.kernel.org/stable/c/601dd3b79769b38d30b693c40afdb2a4b7edf9d0 (opens in a new tab)
- git.kernel.org/stable/c/3969db6b22e3d90d8c5f22ac1a7fe0350a94c136 (opens in a new tab)
- git.kernel.org/stable/c/8c59eeeeffa1524ef57e173a89a1a3ff539888d5 (opens in a new tab)
- git.kernel.org/stable/c/96c4af418586ee9a6aab61738644366426e05316 (opens in a new tab)