CVE-2026-23066: Linux kernel · rxrpc: Fix recvmsg() unconditional requeue
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in cf969bddd6e69c5777fa89dc88402204e72f312a : patch Linux kernel soon.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% 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 cf969bddd6e69c5777fa89dc88402204e72f312a, c198628f3fca5c874d93874c233014d336e09f64, c6cebcb4e0b3140ec2ace45c020a9049527385d1 +4
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 4 Feb 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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AI-suggested
A fix is available and has been applied in multiple Linux kernel commits. Users and administrators should update affected Linux kernel versions to the fixed releases identified by the provided commit hashes. Since this is not a cloud service, manual patching is required. No alternative mitigations are indicated in the advisory.
Description
CVE-2026-23066 is a high-severity vulnerability in the Linux kernel's rxrpc subsystem affecting version 4.11. It involves an unconditional requeue in the recvmsg() function that can corrupt the recvmsg queue, potentially causing use-after-free (UAF) or reference count underrun issues. The flaw occurs when rxrpc_recvmsg() requeues a call even if it is already queued, especially when MSG_DONTWAIT and MSG_PEEK flags are used. The issue has been fixed by ensuring calls are only requeued if not already on the queue and adjusting queue handling accordingly.
References
- git.kernel.org/stable/c/8fd3b5e297854a4da0f273169baf4b1b7b257b97 (opens in a new tab)
- git.kernel.org/stable/c/c198628f3fca5c874d93874c233014d336e09f64 (opens in a new tab)
- git.kernel.org/stable/c/c6cebcb4e0b3140ec2ace45c020a9049527385d1 (opens in a new tab)
- git.kernel.org/stable/c/0464bf75590da75b8413c3e758c04647b4cdb3c6 (opens in a new tab)
- git.kernel.org/stable/c/cf969bddd6e69c5777fa89dc88402204e72f312a (opens in a new tab)
- git.kernel.org/stable/c/930114425065f7ace6e0c0630fab4af75e059ea8 (opens in a new tab)
- git.kernel.org/stable/c/2c28769a51deb6022d7fbd499987e237a01dd63a (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)