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Vulnerability · Published Jul 8, 2026 · Assigned by GitHub_M

CVE-2026-58494Wasmtime: WASI hard links bypass wasmtime-wasi's FilePerms for destination

Medium 6.5

In plain English

A medium-severity incorrect authorization in wasmtime from bytecodealliance. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.2%top 93.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Wasmtime is a runtime for WebAssembly. Prior to 24.0.11, 36.0.12, 45.0.3, and 46.0.1, wasmtime-wasi hard-link creation and renaming check directory permissions but not matching FilePerms on source and destination preopens, allowing a WASI guest with a read-only source file capability to overwrite host files exposed as FilePerms::READ through wasip1, wasip2, or wasip3 filesystem interfaces. This issue is fixed in versions 24.0.11, 36.0.12, 45.0.3, and 46.0.1.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:13rust-wasmtimeno fix listedDEBIAN-CVE-2026-58494
Debian:14rust-wasmtime36.0.12+dfsg-1DEBIAN-CVE-2026-58494
Ubuntu:24.04:LTSrust-wasmtimeno fix listedUBUNTU-CVE-2026-58494
Ubuntu:25.10rust-wasmtimeno fix listedUBUNTU-CVE-2026-58494
Ubuntu:26.04:LTSrust-wasmtimeno fix listedUBUNTU-CVE-2026-58494
Ubuntu:26.10rust-wasmtimeno fix listedUBUNTU-CVE-2026-58494

Affected products (as reported)

VendorProductVersions
bytecodealliance wasmtime < 24.0.11>= 25.0.0, < 36.0.12>= 37.0.0, < 45.0.3>= 46.0.0, < 46.0.1

Weakness: CWE-281, CWE-863 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N

References