High · CVSS 8.8CVE-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 RenameCVE-2026-118688

Answer in brief

CVE-2026-118688 records a High severity (CVSS 8.8) vulnerability in 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. The current sources do not mark it as known exploited. The current feed maps bytecodealliance/wasmtime (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 28, 2026Updated Oct 28, 2026Source checked Oct 28, 2026First seen by HOL Oct 28, 2026Material review Oct 28, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.8
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps bytecodealliance/wasmtime (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
bytecodealliance/wasmtimegeneric	>=0 <36.0.18 \|\| >=37.0.0 <48.0.6 \|\| >=49.0.0 <49.0.3	36.0.18, 48.0.6, 49.0.3

Recommended response

Check inventory. Check lockfiles and deployed manifests for bytecodealliance/wasmtime.
Review the reported fix. Update bytecodealliance/wasmtime to 36.0.18 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 28, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 28, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 28, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.