Oren Yomtov(@orenyomtov):We escaped Docker's hypervisor with three lines of bash. CVE-2026-77179: A container gets complete read and write access to the host filesystem. When you mount a folder into a container, Docker's VMM uses virtio-fs, and the file server runs on the host. Because of a TOCTOU bug, if a container opens a file, deletes it while holding its file handle open, and replaces the parent folder with a symlink, the kernel will follow the symlink to anywhere on the host. Full technical breakdown:

Oren Yomtov

@orenyomtov

security researcher; RSAC, Black Hat, and DEF CON (2 times) speaker

参加 May 2009

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Oren Yomtov@orenyomtov

2026.09.19 07:50

We escaped Docker's hypervisor with three lines of bash. CVE-2026-77179: A container gets complete read and write access to the host filesystem. When you mount a folder into a container, Docker's VMM uses virtio-fs, and the file server runs on the host. Because of a TOCTOU bug, if a container opens a file, deletes it while holding its file handle open, and replaces the parent folder with a symlink, the kernel will follow the symlink to anywhere on the host. Full technical breakdown: