CVE-2026-118688

high

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.

References

https://www.vulncheck.com/advisories/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

https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-m9f7-9w4p-gv38

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-112393

Details

Source: Mitre, NVD

Published: 2026-10-28

Updated: 2026-10-28

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:N/AC:H/Au:S/C:C/I:C/A:P

Severity: Medium

CVSS v3

Base Score: 7.9

Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:L

Severity: High

CVSS v4

Base Score: 8.8

Vector: 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

Severity: High

EPSS

EPSS: 0.00242