CVE-2026-72491Network attack vector

Kernel crash via unlocked RDMA state transitions

Published Aug 15, 2026 · Updated Aug 15, 2026

Use-after-free in the Linux kernel 9P RDMA transport allows remote attackers to crash the kernel through concurrent teardown events. recv_done() and p9_cm_event_handler() update rdma->state without req_lock while rdma_request() changes it under that lock, so FLUSHING can be overwritten by CLOSING and freed request objects can remain referenced. Exploitation requires an existing 9P RDMA mount and a malicious or compromised remote server; bounded outcomes include transport failure, kernel hang, or kernel crash.

CVSS severity9.8
Critical
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel 9P RDMA transport allows remote attackers to crash the kernel through concurrent teardown events. recv_done() and p9_cm_event_handler() update rdma->state without req_lock while rdma_request() changes it under that lock, so FLUSHING can be overwritten by CLOSING and freed request objects can remain referenced. Exploitation requires an existing 9P RDMA mount and a malicious or compromised remote server; bounded outcomes include transport failure, kernel hang, or kernel crash.

The record

CVE
CVE-2026-72491
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, CWE-362, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3479b3c35e82ed10aa0ca2ee9e78c4eded06ba62
  2. Affected versionversion=4.14.132 <4.15
  3. Affected versionversion=4.19.57 <4.20
  4. Affected versionversion=4.20
  5. Affected versionversion=4.4.185 <4.5
  6. Affected versionversion=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <13bf9879b778b2f4b260b45bed18f31806120d1e
  7. Affected versionversion=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <151f8cf5b23d8a534d884432a82a6d54d5a61989
  8. Affected versionversion=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <3970a19a80de530b801b6256354d4a529a9a2d6c
  9. Affected versionversion=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <4cee2b8766045059d5e0b8114837b4a8efe827ac
  10. Affected versionversion=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <5424138848eb7d7d8a7196676e90a2cbf2142454
  11. Affected versionversion=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <7d54894a1ee265a72d70f7cae1da6cc774cccc71
  12. Affected versionversion=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <8aadc136d8e8d8fc95d7982d213cfe2234dfcf2b
  13. Affected versionversion=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <ebbcbe5c0db215feecc17def06178da443f4eea6
  14. Affected versionversion=4.9.185 <4.10
  15. Affected versionversion=9e69c673fe077b8dc491cd8406c9bdcb1f76dee2
  16. Affected versionversion=c01ddaa54d7411e964ffd250c018d8469c5852f2
  17. Affected versionversion=e48e7e27e4dfd00c81e0381e7cee610cce021452

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3479b3c35e82ed10aa0ca2ee9e78c4eded06ba62; version=4.14.132 <4.15; version=4.19.57 <4.20; version=4.20; version=4.4.185 <4.5; version=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <13bf9879b778b2f4b260b45bed18f31806120d1e; version=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <151f8cf5b23d8a534d884432a82a6d54d5a61989; version=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <3970a19a80de530b801b6256354d4a529a9a2d6c; version=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <4cee2b8766045059d5e0b8114837b4a8efe827ac; version=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <5424138848eb7d7d8a7196676e90a2cbf2142454; version=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <7d54894a1ee265a72d70f7cae1da6cc774cccc71; version=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <8aadc136d8e8d8fc95d7982d213cfe2234dfcf2b; version=473c7dd1d7b59ff8f88a5154737e3eac78a96e5b <ebbcbe5c0db215feecc17def06178da443f4eea6; version=4.9.185 <4.10; version=9e69c673fe077b8dc491cd8406c9bdcb1f76dee2; version=c01ddaa54d7411e964ffd250c018d8469c5852f2; version=e48e7e27e4dfd00c81e0381e7cee610cce021452

Published CVSS scores

5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
9.8Linux CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.3Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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