CVE-2026-64015: Linux kernel · security/keys: fix missed RCU read section on lookup
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in cefa4265b11176c897a7d9e8e54d89e3701c5584 : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% 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 cefa4265b11176c897a7d9e8e54d89e3701c5584, 66288dcadf80974436250e9f70ed848836b835b5, 5659e6923cb72f8e18e8b539109ab512455fe195 +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Jul 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
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Description
In the Linux kernel, the following vulnerability has been resolved: security/keys: fix missed RCU read section on lookup Nicholas Carlini reports that the keyring code calls assoc_array_find() in find_key_to_update() without holding the RCU read lock, while the assoc_array_gc() code really is designed around removing the node from the tree and then freeing it after an RCU grace-period. The regular key handling doesn't see this because holding the keyring semaphore hides any lifetime issues, but the persistent key handling uses a different model. Instead of extending the keyring locking, just do the simple RCU locking that the assoc_array was designed for.
References
- git.kernel.org/stable/c/4c5d407ba3ff7f30561ff73ba1b07ed70c864edc (opens in a new tab)
- git.kernel.org/stable/c/cefa4265b11176c897a7d9e8e54d89e3701c5584 (opens in a new tab)
- git.kernel.org/stable/c/5659e6923cb72f8e18e8b539109ab512455fe195 (opens in a new tab)
- git.kernel.org/stable/c/50bb3435a5e627bfbdc52eb4536f49f88b3486b8 (opens in a new tab)
- git.kernel.org/stable/c/66288dcadf80974436250e9f70ed848836b835b5 (opens in a new tab)
- git.kernel.org/stable/c/43a1e3744548e6fd85873e6fb43e293eb4010694 (opens in a new tab)