What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.5 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: 2026-07-08 · updated 2026-10-25
• Weakness: CWE-281

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 products

• bytecodealliance wasmtime: before 24.0.11; from 25.0.0, < 36.0.12; from 37.0.0, < 45.0.3; from 46.0.0, < 46.0.1

References

• https://github.com/bytecodealliance/wasmtime/commit/5ddfd5f1ef28f2041fa07d237ad0336e167b0e0c
• https://github.com/bytecodealliance/wasmtime/commit/7db94cdcf0c79cb3dfde884b534b653f2dd83367
• https://github.com/bytecodealliance/wasmtime/commit/8a250aac0962ca1364b5f16525720e9d0b39edcd
• https://github.com/bytecodealliance/wasmtime/commit/d3ceb56ec35f39e02496eeb4e2d9c7f4fb964d9e
• https://github.com/bytecodealliance/wasmtime/releases/tag/v24.0.11
• https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.12
• https://github.com/bytecodealliance/wasmtime/releases/tag/v45.0.3
• https://github.com/bytecodealliance/wasmtime/releases/tag/v46.0.1
• https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-4ch3-9j33-3pmj

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