CVE-2025-11233

Rust standard library didn't detect all path separators on Cygwin

State: Published
Severity: 6.3 Medium
Published: Oct 1, 2025
Updated: Oct 1, 2025
Reserved: Oct 1, 2025

Description

Starting from Rust 1.87.0 and before Rust 1.89.0, the tier 3 Cygwin target (`x86_64-pc-cygwin`) didn't correctly handle path separators, causing the standard library's Path API to ignore path components separated by backslashes. Due to this, programs compiled for Cygwin that validate paths could misbehave, potentially allowing path traversal attacks or malicious filesystem operations.

Rust 1.89.0 fixes the issue by handling both Win32 and Unix style paths in the standard library for the Cygwin target.

While we assess the severity of this vulnerability as "medium", please note that the tier 3 Cygwin compilation target is only available when building it from source: no pre-built binaries are distributed by the Rust project, and it cannot be installed through Rustup. Unless you manually compiled the `x86_64-pc-cygwin` target you are not affected by this vulnerability. Users of the tier 1 MinGW target (`x86_64-pc-windows-gnu`) are also explicitly not affected.

Scores

CVSS	Score	Vector	Source
4.0	6.3 Medium	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/AU:Y/RE:L/U:Green	rust

Weaknesses

CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Affected Products

Product	Versions
stdRust Project	1.87.0 to before 1.89.0Affected

References

https://github.com/rust-lang/rust/pull/141864patch
https://groups.google.com/g/rustlang-security-announcements/c/oT9zCvLLYkwvendor-advisory

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.