runc container escape with malicious config due to /dev/console mount and related races

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

7.3 · 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 · score source

EPSS

• CVE-2025-52565: 0.81% estimated exploitation activity in the next 30 days; percentile 56.99 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact

This attack is very similar in concept and application to CVE-2025-31133, except that it attacks a similar vulnerability in a different target (namely, the bind-mount of /dev/pts/$n to /dev/console as configured for all containers that allocate a console). In runc version 1.0.0-rc3 and later, due to insufficient checks when bind-mounting /dev/pts/$n to /dev/console inside the container, an attacker can trick runc into bind-mounting paths which would normally be made read-only or be masked onto a path that the attacker can write to. This happens after pivotroot(2), so this cannot be used to write to host files directly -- however, as with CVE-2025-31133, this can load to denial of service of the host or a container breakout by providing the attacker with a writable copy of /proc/sysrq-trigger or /proc/sys/kernel/corepattern (respectively). The reason that the attacker can gain write access to these files is because the /dev/console bind-mount happens before maskedPaths and…

Published by the source

5 Nov 2025, 17:34 UTC

Last modified by the source

6 Nov 2025, 23:12 UTC

Source last checked

26 Oct 2026, 15:13 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-qw9x-cqr3-wc7r

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# Patch Next advisory brief: CVE-2025-52565

Advisory: runc container escape with malicious config due to /dev/console mount and related races
IDs: CVE-2025-52565, GHSA-qw9x-cqr3-wc7r
Record: https://patchnext.com/advisories/cve-2025-52565 (revision 1, source checked 26 Oct 2026, 15:13 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/opencontainers/runc 1.4.0-rc.3, 1.3.3, 1.2.8. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/opencontainers/runc: affected >= 1.0.0-rc3, <= 1.2.7; >= 1.3.0-rc.1, <= 1.3.2; >= 1.4.0-rc.1, <= 1.4.0-rc.2; fixed in 1.2.8, 1.3.3, 1.4.0-rc.3

## Suggested inspection (read-only)
- Go github.com/opencontainers/runc: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/opencontainers/runc.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-qw9x-cqr3-wc7r (GitHub-reviewed advisory GHSA-qw9x-cqr3-wc7r lists affected ranges: Go github.com/opencontainers/runc >=1.0.0-rc3 =1.3.0-rc.1 =1.4.0-rc.1 <=1.4.0-rc.2)

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