CVE-2026-58494: CWE-281: Improper Preservation of Permissions in bytecodealliance wasmtime
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.
AI Analysis
Technical Summary
CVE-2026-58494 affects the wasmtime runtime for WebAssembly. The vulnerability arises because wasmtime-wasi checks directory permissions but does not verify matching file permissions on source and destination preopens during hard-link creation and renaming operations. This flaw permits a WASI guest with only read-only access to a source file to overwrite host files that are exposed as read-only through wasip1, wasip2, or wasip3 filesystem interfaces. The issue is addressed in wasmtime versions 24.0.11, 36.0.12, 45.0.3, and 46.0.1.
Potential Impact
An attacker controlling a WASI guest environment with read-only access to a source file can exploit this vulnerability to overwrite host files that should be read-only. This results in integrity loss (high impact on integrity) of host files without elevating confidentiality or availability impacts. The vulnerability requires local access (AV:L) and low privileges (PR:L) but no user interaction (UI:N).
Mitigation Recommendations
Fixed versions 24.0.11, 36.0.12, 45.0.3, and 46.0.1 are available and should be applied to remediate this vulnerability. Since the vendor advisory indicates these versions fix the issue, upgrading to these or later versions is the recommended mitigation. Patch status is confirmed by the version fixes stated in the description. No additional vendor advisory content is provided.
CVE-2026-58494: CWE-281: Improper Preservation of Permissions in bytecodealliance wasmtime
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.
CVSS v3.1
Score 6.5medium
Affected software
pkg:github/bytecodealliance/wasmtimeRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-58494 affects the wasmtime runtime for WebAssembly. The vulnerability arises because wasmtime-wasi checks directory permissions but does not verify matching file permissions on source and destination preopens during hard-link creation and renaming operations. This flaw permits a WASI guest with only read-only access to a source file to overwrite host files that are exposed as read-only through wasip1, wasip2, or wasip3 filesystem interfaces. The issue is addressed in wasmtime versions 24.0.11, 36.0.12, 45.0.3, and 46.0.1.
Potential Impact
An attacker controlling a WASI guest environment with read-only access to a source file can exploit this vulnerability to overwrite host files that should be read-only. This results in integrity loss (high impact on integrity) of host files without elevating confidentiality or availability impacts. The vulnerability requires local access (AV:L) and low privileges (PR:L) but no user interaction (UI:N).
Mitigation Recommendations
Fixed versions 24.0.11, 36.0.12, 45.0.3, and 46.0.1 are available and should be applied to remediate this vulnerability. Since the vendor advisory indicates these versions fix the issue, upgrading to these or later versions is the recommended mitigation. Patch status is confirmed by the version fixes stated in the description. No additional vendor advisory content is provided.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-30T20:21:25.812Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4eb691c9d9e3dbe3b687a1
Added to database: 07/08/2026, 20:44:01 UTC
Last enriched: 07/16/2026, 10:13:39 UTC
Last updated: 08/22/2026, 10:52:10 UTC
Views: 102
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