CVE-2026-45920: Linux kernel · ext4: fix dirtyclusters double decrement on fs shutdown
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in dbc4e10619ed87a50e637b96f2e574df36a7a769 : update Linux kernel when convenient.
Data as of 6 Nov 2026, 16:05 UTC
Rated Low by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- 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
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in dbc4e10619ed87a50e637b96f2e574df36a7a769, ca408af08544d96769c93a3d81a7f63f61129e95, 81982a11406c5da6c6e2b188028e7056e16b7128 +5
Exploitation evidence
Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 6 Nov 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
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AI-suggested
A fix is available and has been applied in multiple Linux kernel commits. Users should update to a Linux kernel version that includes the fix identified by the listed commit hashes. No additional mitigation is required beyond applying the official patch.
Description
A vulnerability in the Linux kernel ext4 filesystem code caused a double decrement of the dirty clusters counter during filesystem shutdown, leading to a warning and inconsistent internal state. This was due to an error path where the dirty clusters counter was decremented twice, resulting in a negative counter value. The issue was fixed by consolidating the counter decrement to a single location in the code, clarifying cluster reservation ownership.
References
- git.kernel.org/stable/c/523d5a4df3c649fa305c89efb552ec62a1ce9d3d (opens in a new tab)
- git.kernel.org/stable/c/ca408af08544d96769c93a3d81a7f63f61129e95 (opens in a new tab)
- git.kernel.org/stable/c/55576fa14771d33994c29a9ae960e07bb3f56c20 (opens in a new tab)
- git.kernel.org/stable/c/dbc4e10619ed87a50e637b96f2e574df36a7a769 (opens in a new tab)
- git.kernel.org/stable/c/61e372122b6d95aec940fdaea0a16f988f359897 (opens in a new tab)
- git.kernel.org/stable/c/3924aea2c33df3864929c1acd178bfc29d8f005f (opens in a new tab)
- git.kernel.org/stable/c/81982a11406c5da6c6e2b188028e7056e16b7128 (opens in a new tab)
- git.kernel.org/stable/c/94a8cea54cd935c54fa2fba70354757c0fc245e3 (opens in a new tab)