What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 7.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-28 · updated 2026-10-28
• Weakness: CWE-61

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.

Affected products

• bytecodealliance wasmtime: before 36.0.18; from 37.0.0 before 48.0.6; from 49.0.0 before 49.0.3 — fixed in 36.0.18, 48.0.6, 49.0.3

How to fix

Upgrade to a fixed version: bytecodealliance wasmtime 36.0.18, 48.0.6, 49.0.3. Check the vendor advisory for mitigations.

References

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

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