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VulnerabilityPublished Updated

CVE-2026-89545: Linux kernel · sunrpc: defer rq_argp and rq_resp free until after RCU grace period

Affects Linux kernelSource CVE Database V5

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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

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CNA (Linux)CVSS 3.17.8
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:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 11 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 812443865c5fc255363d4a684a62c086af1addca, < e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090
Fixed in
  • e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090
LinuxLinuxAffected
  • ≥ 812443865c5fc255363d4a684a62c086af1addca, < c977158237bccc3d2512d5b17c47ee3760dc8839
Fixed in
  • c977158237bccc3d2512d5b17c47ee3760dc8839
LinuxLinuxAffected
  • ≥ 812443865c5fc255363d4a684a62c086af1addca, < c479bde671cbe2f9e152834a8b0eb7c3c295bbaf
Fixed in
  • c479bde671cbe2f9e152834a8b0eb7c3c295bbaf
LinuxLinuxAffected
  • ≥ 812443865c5fc255363d4a684a62c086af1addca, < 08bc49e0541260bf294962cf889a32a2d2713ad6
Fixed in
  • 08bc49e0541260bf294962cf889a32a2d2713ad6
LinuxLinuxAffected
  • ≥ 812443865c5fc255363d4a684a62c086af1addca, < 0ea49d69aa806008b2424c8cf21cf746b9963967
Fixed in
  • 0ea49d69aa806008b2424c8cf21cf746b9963967
LinuxLinuxAffected
  • =3.19
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

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