CVE-2026-5223: CWE-61 UNIX symbolic link (symlink) following in Rust Project Cargo
CVE-2026-5223 is a medium severity vulnerability in Rust's Cargo tool where symlinks inside crate tarballs from third-party registries are incorrectly handled. This flaw allows a malicious crate to override the source code of another crate from the same registry. Users of the official crates.io registry are not affected because it forbids uploading crates containing symlinks.
AI Analysis
Technical Summary
Cargo, the Rust package manager, incorrectly processes symbolic links within crate tarballs downloaded from third-party registries. This improper handling can be exploited by a malicious crate to overwrite the source code of another crate from the same registry. The vulnerability is identified as CWE-61 (Improper Handling of Symbolic Links). Official crates.io users are not impacted due to restrictions on symlink uploads. The vulnerability has a CVSS 4.0 base score of 6.5, indicating medium severity. There is no vendor advisory or patch information available at this time.
Potential Impact
A malicious crate from a third-party registry can override the source code of another crate, potentially leading to supply chain compromise or code integrity issues for users relying on such registries. Users of crates.io are not impacted. There are no known exploits in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should avoid using third-party registries that allow symlinks in crates or verify crate contents before use. Users relying solely on crates.io are not affected and require no action.
CVE-2026-5223: CWE-61 UNIX symbolic link (symlink) following in Rust Project Cargo
Description
CVE-2026-5223 is a medium severity vulnerability in Rust's Cargo tool where symlinks inside crate tarballs from third-party registries are incorrectly handled. This flaw allows a malicious crate to override the source code of another crate from the same registry. Users of the official crates.io registry are not affected because it forbids uploading crates containing symlinks.
CVSS v4.0
Score 6.5medium
Affected software
pkg:cargo/github/rust-lang/cargoRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Cargo, the Rust package manager, incorrectly processes symbolic links within crate tarballs downloaded from third-party registries. This improper handling can be exploited by a malicious crate to overwrite the source code of another crate from the same registry. The vulnerability is identified as CWE-61 (Improper Handling of Symbolic Links). Official crates.io users are not impacted due to restrictions on symlink uploads. The vulnerability has a CVSS 4.0 base score of 6.5, indicating medium severity. There is no vendor advisory or patch information available at this time.
Potential Impact
A malicious crate from a third-party registry can override the source code of another crate, potentially leading to supply chain compromise or code integrity issues for users relying on such registries. Users of crates.io are not impacted. There are no known exploits in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should avoid using third-party registries that allow symlinks in crates or verify crate contents before use. Users relying solely on crates.io are not affected and require no action.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- rust
- Date Reserved
- 2026-03-31T12:07:41.420Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a141902a5ae1af1aa7fdd89
Added to database: 05/25/2026, 09:40:18 UTC
Last enriched: 06/13/2026, 10:24:36 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 71
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