8.8 High

CVE-2026-118688 Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 Sandbox Escape via Symlink Rename

Description

wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox and read or write them.

CVSS 4.0 detail

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L

Exploitable remotely over the network, with an ordinary account and if a user takes an action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector: Network
Attack complexity: Low
Attack requirements: Present
Privileges required: Low
Interaction: Passive
Confidentiality: High
Integrity: High
Availability: Low
Confidentiality of other systems: High
Integrity of other systems: High
Availability of other systems: Low

Affected products and versions

Product	Affected versions	Fixed in
wasmtime 49.0	49.0.0 → < 49.0.3	49.0.3
wasmtime 48.0	earliest → < 48.0.6	48.0.6
wasmtime 37.0	37.0.0 → < 48.0.6	48.0.6
wasmtime 36.0	earliest → < 36.0.18	36.0.18