CVE-2026-74618

Local denial of service via repeated binfmt_misc warning

Published Aug 22, 2026 · Updated Aug 22, 2026

Reachable assertion in the Linux kernel's binfmt_misc component allows local users to crash systems via cross-user-namespace mounts. bm_fill_super() uses WARN_ON() when the fsconfig creator's user namespace differs from the namespace recorded by fsopen(), although that handoff is permitted. An unprivileged user can pass the fscontext descriptor to a parent and loop the warning to flood logs and taint the kernel; panic_on_warn causes a kernel panic.

CVSS severity5.5
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in the Linux kernel's binfmt_misc component allows local users to crash systems via cross-user-namespace mounts. bm_fill_super() uses WARN_ON() when the fsconfig creator's user namespace differs from the namespace recorded by fsopen(), although that handoff is permitted. An unprivileged user can pass the fscontext descriptor to a parent and loop the warning to flood logs and taint the kernel; panic_on_warn causes a kernel panic.

The record

CVE
CVE-2026-74618
Published
Aug 22, 2026
Updated
Aug 22, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-617, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 22, 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=21ca59b365c091d583f36ac753eaa8baf947be6f <047f927f54c6c17593e93aafe82dcb7acdda2a71
  2. Affected versionversion=21ca59b365c091d583f36ac753eaa8baf947be6f <24e95a24f151ce40d5fc1b3a6cefbcda8ded736c
  3. Affected versionversion=21ca59b365c091d583f36ac753eaa8baf947be6f <37cf5cf1320a84a17225a1690547b8a0812ca94e
  4. Affected versionversion=21ca59b365c091d583f36ac753eaa8baf947be6f <79fdf39f1a31f88cb3833b6f8091fbf6acdca2c6
  5. Affected versionversion=6.7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=21ca59b365c091d583f36ac753eaa8baf947be6f <047f927f54c6c17593e93aafe82dcb7acdda2a71; version=21ca59b365c091d583f36ac753eaa8baf947be6f <24e95a24f151ce40d5fc1b3a6cefbcda8ded736c; version=21ca59b365c091d583f36ac753eaa8baf947be6f <37cf5cf1320a84a17225a1690547b8a0812ca94e; version=21ca59b365c091d583f36ac753eaa8baf947be6f <79fdf39f1a31f88cb3833b6f8091fbf6acdca2c6; version=6.7

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.

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No observations available

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

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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