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USN-7851-2: runC regression

USN-7851-2: runC regression

Ubuntu • November 24, 2025

USN-7851-1 fixed vulnerabilities in runC. The introduction of a new upstream release has caused regressions in runc-app and runc-stable. This update fixes the problem. Original advisory details: Lei Wang and Li Fubang discovered that runC incorrectly handled masked paths. An attacker could possibly replace a container's /dev/null with a symlink to some other procfs file and possibly escape a container. ( CVE-2025-31133 ) Lei Wang and Li Fubang discovered that runC incorrectly handled the /dev/console bind-mounts. An attacker could potentially exploit this issue to build-mount a symlink and escape a container. ( CVE-2025-52565 ) Li Fubang and Tõnis Tiigi discovered that the fix for CVE-2019-16884 was incomplete. An attacker could possibly use this issue to cause a denial of service or escape the...

USN-7851-1 fixed vulnerabilities in runC. The introduction of a new upstream release has caused regressions in runc-app and runc-stable. This update fixes the problem.

Original advisory details:

Lei Wang and Li Fubang discovered that runC incorrectly handled masked paths. An attacker could possibly replace a container's /dev/null with a symlink to some other procfs file and possibly escape a container. ( CVE-2025-31133 )

Lei Wang and Li Fubang discovered that runC incorrectly handled the /dev/console bind-mounts. An attacker could potentially exploit this issue to build-mount a symlink and escape a container. ( CVE-2025-52565 )

Li Fubang and Tõnis Tiigi discovered that the fix for CVE-2019-16884 was incomplete. An attacker could possibly use this issue to cause a denial of service or escape the...

USN-7851-1 fixed vulnerabilities in runC. The introduction of a new upstream release has caused regressions in runc-app and runc-stable. This update fixes the problem. Original advisory details: Lei Wang and Li Fubang discovered that runC incorrectly handled masked paths. An attacker could possibly replace a container's /dev/null with a symlink to some other procfs file and possibly escape a container. ( CVE-2025-31133 ) Lei Wang and Li Fubang discovered that runC incorrectly handled the /dev/console bind-mounts. An attacker could potentially exploit this issue to build-mount a symlink and escape a container. ( CVE-2025-52565 ) Li Fubang and Tõnis Tiigi discovered that the fix for CVE-2019-16884 was incomplete. An attacker could possibly use this issue to cause a denial of service or escape the container. ( CVE-2025-52881 )

USN-7851-1 fixed vulnerabilities in runC. The introduction of a new upstream release has caused regressions in runc-app and runc-stable. This update fixes the problem.

Original advisory details:

Lei Wang and Li Fubang discovered that runC incorrectly handled masked paths. An attacker could possibly replace a container's /dev/null with a symlink to some other procfs file and possibly escape a container. ( CVE-2025-31133 )

Lei Wang and Li Fubang discovered that runC incorrectly handled the /dev/console bind-mounts. An attacker could potentially exploit this issue to build-mount a symlink and escape a container. ( CVE-2025-52565 )

Li Fubang and Tõnis Tiigi discovered that the fix for CVE-2019-16884 was incomplete. An attacker could possibly use this issue to cause a denial of service or escape the container. ( CVE-2025-52881 )

In general, a standard system update will make all the necessary changes.

The problem can be corrected by updating your system to the following package versions:

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