GHSA-fjx5-qpf4-xjf2 — borsh
GHSA-fjx5-qpf4-xjf2 is a remote code execution vulnerability in borsh. A fix is available for borsh — see the affected versions and patch details below.
Parsing borsh messages with ZST which are not-copy/clone is unsound
Real-World Exposure
borshReal-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
Affected versions of borsh cause undefined behavior when zero-sized-types (ZST) are parsed and the Copy/Clone traits are not implemented/derived. For instance if 1000 instances of a ZST are deserialized, and the ZST is not copy (this can be achieved through a singleton), then accessing/writing to deserialized data will cause a segmentation fault.
There is currently no way for borsh to read data without also providing a Rust type. Therefore, if you are not using ZST for serialization, then you are not affected by this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | borsh | all versions | 1.0.0-alpha.1cargo update -p borsh --precise 1.0.0-alpha.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for borsh, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update borsh to 1.0.0-alpha.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fjx5-qpf4-xjf2 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-fjx5-qpf4-xjf2 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-fjx5-qpf4-xjf2. 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-fjx5-qpf4-xjf2 in your dependencies?
O3 Security finds GHSA-fjx5-qpf4-xjf2 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.