CVE-2025-52881

Container escape via raced procfs write redirection

Published Nov 6, 2025 · Updated Nov 6, 2025

Race condition in runc 1.2.7, 1.3.2, and 1.4.0-rc.2 allows local users to escape containers via redirected procfs writes. During procfs writes, runc resolves paths through a container-shared mount and then writes after an attacker races a symlink or bind mount to a different real procfs file. The attacker must control a container image or custom mount configuration and trigger parallel container execution; successful redirection can suppress LSM labels, crash or hang the host, or write core_pattern for host-root code execution.

CVSS severity7.3
High
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in runc 1.2.7, 1.3.2, and 1.4.0-rc.2 allows local users to escape containers via redirected procfs writes. During procfs writes, runc resolves paths through a container-shared mount and then writes after an attacker races a symlink or bind mount to a different real procfs file. The attacker must control a container image or custom mount configuration and trigger parallel container execution; successful redirection can suppress LSM labels, crash or hang the host, or write core_pattern for host-root code execution.

The record

CVE
CVE-2025-52881
Published
Nov 6, 2025
Updated
Nov 6, 2025
Vendor
Open Container Initiative
Product
runc
Classifications
CWE-363, CWE-61, T1611
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 6, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 2025Record 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=<= 1.2.7, < 1.2.8
  2. Affected versionversion=<= 1.3.2, < 1.3.3
  3. Affected versionversion=<= 1.4.0-rc.2, < 1.4.0-rc.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Open Container Initiative · runcversion=<= 1.2.7, < 1.2.8; version=<= 1.3.2, < 1.3.3; version=<= 1.4.0-rc.2, < 1.4.0-rc.3

Published CVSS scores

7.3GitHub, Inc.CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
7.5NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-363Race Condition Enabling Link Following
CWE-61UNIX Symbolic Link (Symlink) Following
T1611Escape to Host

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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