GHSA-rfj2-q3h3-hm5j is a low-severity (CVSS 3.9) Path Traversal vulnerability in cargo. A fix is available for cargo — see the affected versions and patch details below.
Cargo extracting malicious crates can corrupt arbitrary files
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-rfj2-q3h3-hm5j.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-rfj2-q3h3-hm5j plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
cargo🦀cargoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
The Rust Security Response WG was notified that Cargo did not prevent extracting some malformed packages downloaded from alternate registries. An attacker able to upload packages to an alternate registry could corrupt arbitary files when Cargo downloaded the package.
The severity of this vulnerability is "low" for users of alternate registries. Users relying on crates.io are not affected.
Note that by design Cargo allows code execution at build time, due to build scripts and procedural macros. The vulnerabilities in this advisory allow performing a subset of the possible damage in a harder to track down way. Your dependencies must still be trusted if you want to be protected from attacks, as it's possible to perform the same attacks with build scripts and procedural macros.
Arbitrary file corruption
After a package is downloaded, Cargo extracts its source code in the ~/.cargo folder on disk, making it available to the Rust projects it builds. To record when an extraction is successfull, Cargo writes "ok" to the .cargo-ok file at the root of the extracted source code once it extracted all the files.
It was discovered that Cargo allowed packages to contain a .cargo-ok symbolic link, which Cargo would extract. Then, when Cargo attempted to write "ok" into .cargo-ok, it would actually replace the first two bytes of the file the symlink pointed to with ok. This would allow an attacker to corrupt one file on the machine using Cargo to extract the package.
Affected versions
The vulnerability is present in all versions of Cargo. Rust 1.64, to be released on September 22nd, will include a fix for it.
Since the vulnerability is just a more limited way to accomplish what a malicious build scripts or procedural macros can do, we decided not to publish Rust point releases backporting the security fix. Patch files are available for Rust 1.63.0 are available in the wg-security-response repository for people building their own toolchain.
Mitigations
We recommend users of alternate registries to excercise care in which package they download, by only including trusted dependencies in their projects. Please note that even with these vulnerabilities fixed, by design Cargo allows arbitrary code execution at build time thanks to build scripts and procedural macros: a malicious dependency will be able to cause damage regardless of these vulnerabilities.
crates.io implemented server-side checks to reject these kinds of packages years ago, and there are no packages on crates.io exploiting these vulnerabilities. crates.io users still need to excercise care in choosing their dependencies though, as remote code execution is allowed by design there as well.
Acknowledgements
We want to thank Ori Hollander from JFrog Security Research for responsibly disclosing this to us according to the Rust security policy.
We also want to thank Josh Triplett for developing the fixes, Weihang Lo for developing the tests, and Pietro Albini for writing this advisory. The disclosure was coordinated by Pietro Albini and Josh Stone.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | cargo | all versions | 0.65.0cargo update -p cargo --precise 0.65.0 |
| 🦀crates.io | cargo | ≥ 0.66.0&&< 0.67.0 | 0.67.0cargo update -p cargo --precise 0.67.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for cargo, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update cargo to 0.65.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rfj2-q3h3-hm5j is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-rfj2-q3h3-hm5j can be triaged on real exposure rather than presence alone.
Tailored to GHSA-rfj2-q3h3-hm5j. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-rfj2-q3h3-hm5j in your dependencies?
O3 Security finds GHSA-rfj2-q3h3-hm5j across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.