CVE-2026-89545: Linux kernel · sunrpc: defer rq_argp and rq_resp free until after RCU grace period
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090 : patch Linux kernel soon.
Data as of 30 Oct 2026, 13:04 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 7.8 |
|---|
- 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 e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090, c977158237bccc3d2512d5b17c47ee3760dc8839, c479bde671cbe2f9e152834a8b0eb7c3c295bbaf +2
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 11 Sep 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 30 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– |
AI-suggested
A fix is available and has been applied in the Linux kernel commits identified by hashes e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090, c977158237bccc3d2512d5b17c47ee3760dc8839, c479bde671cbe2f9e152834a8b0eb7c3c295bbaf, 08bc49e0541260bf294962cf889a32a2d2713ad6, and 0ea49d69aa806008b2424c8cf21cf746b9963967. Users and administrators should update to a fixed kernel version containing these commits to remediate the vulnerability. No alternative mitigations are indicated.
Description
CVE-2026-89545 is a use-after-free vulnerability in the Linux kernel's sunrpc subsystem. The flaw arises because rq_argp and rq_resp are freed synchronously while the rqstp struct is freed asynchronously via RCU, allowing RCU readers to access freed memory. This can lead to high-impact consequences including confidentiality, integrity, and availability violations. The issue has been fixed by deferring the freeing of rq_argp and rq_resp until after the RCU grace period alongside the struct free.
References
- git.kernel.org/stable/c/c977158237bccc3d2512d5b17c47ee3760dc8839 (opens in a new tab)
- git.kernel.org/stable/c/0ea49d69aa806008b2424c8cf21cf746b9963967 (opens in a new tab)
- git.kernel.org/stable/c/08bc49e0541260bf294962cf889a32a2d2713ad6 (opens in a new tab)
- git.kernel.org/stable/c/e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090 (opens in a new tab)
- git.kernel.org/stable/c/c479bde671cbe2f9e152834a8b0eb7c3c295bbaf (opens in a new tab)