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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-47261 Detail

Description

Wasmtime is a runtime for WebAssembly. In versions prior to 24.0.9, 36.0.10, and 44.0.2, when a filesystem preopen is given DirPerms::all() and FilePerms::READ without FilePerms::WRITE, this access control mechanism can be bypassed via the wasip2 descriptor.open-at or wasip1 path_open interfaces by opening a file with only the OpenFlags::TRUNCATE oflag. The root cause is that the clause handling OpenFlags::TRUNCATE in crates/wasi/src/filesystem.rs (Dir::open_at, lines 967–969) did not set open_mode |= OpenMode::WRITE;, which is later used for the access control check against FilePerms to determine whether opening the file is permitted; the single-line fix adds that missing assignment, after which the affected calls correctly fail with error-code.not-permitted and ERRNO_PERM respectively. Only wasmtime-wasi embeddings that combine DirPerms::MUTATE with FilePerms::READ are affected by this bug. In particular, the Wasmtime project's wasmtime-cli's use of wasmtime-wasi is not affected, because it always sets FilePerms::all() for all preopens. This issue has been fixed in versions 24.0.9, 36.0.10 and44.0.2.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/bytecodealliance/wasmtime/releases/tag/v24.0.9 GitHub, Inc. Release Notes 
https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.10 GitHub, Inc. Release Notes 
https://github.com/bytecodealliance/wasmtime/releases/tag/v44.0.2 GitHub, Inc. Release Notes 
https://github.com/bytecodealliance/wasmtime/releases/tag/v45.0.0 GitHub, Inc. Release Notes 
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-2r75-cxrj-cmph GitHub, Inc. Mitigation  Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
NVD-CWE-noinfo Insufficient Information cwe source acceptance level NIST  
CWE-284 Improper Access Control GitHub, Inc.  

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Change History

4 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-47261
NVD Published Date:
06/15/2026
NVD Last Modified:
06/17/2026
Source:
GitHub, Inc.