CVE-2025-52565: container escape due to /dev/console mount and related races

Should you act?

Normal patch cycle

No exploitation signal; fix it in your next routine update if you are affected. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.6%, percentile 46: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 46% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Needs local access needed. Lower urgency for most teams unless an attacker could already run code on the machine.
• Editorial verdict: Patch this week. runc Container Escapes: Three Mount-Race CVEs Fixed — Not remotely exploitable and not seen in attacks, but anyone who runs or builds images they do not fully trust (CI runners, multi-tenant clusters) should roll out patched runc this week.

What it is

runc is a CLI tool for spawning and running containers according to the OCI specification. Versions 1.0.0-rc3 through 1.2.7, 1.3.0-rc.1 through 1.3.2, and 1.4.0-rc.1 through 1.4.0-rc.2, due to insufficient checks when bind-mounting /dev/pts/$n to /dev/console inside the container, an attacker can trick runc into bind-mounting paths which would normally be made read-only or be masked onto a path that the attacker can write to. This attack is very similar in concept and application to CVE-2025-31133, except that it attacks a similar vulnerability in a different target (namely, the bind-mount of /dev/pts/$n to /dev/console as configured for all containers that allocate a console). 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). This issue is fixed in versions 1.2.8, 1.3.3 and 1.4.0-rc.3.

Weakness type: CWE-61, CWE-363.

Product: opencontainers runc · Assigned by: GitHub_M · Published: 2025-11-06

Affected and fixed versions

Severity scores

• Attack vector: local access needed
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: passive

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable no, technical impact partial.
• FIRST EPSS (model of 2026-10-21): 0.57% probability of exploitation activity in the next 30 days; percentile 46.

Timeline

• 2025-11-05 — erroneo.us brief: runc Container Escapes: Three Mount-Race CVEs Fixed
• 2025-11-06 — CVE record last updated
• 2025-11-06 — CVE record published by GitHub_M

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. CVE.org record CVE-2025-52565 cve.org
2. NVD entry CVE-2025-52565 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
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