GHSA-7v4j-8wvr-v55r
`array!` macro is unsound when its length is impure constant
Blast Radius
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Description
Affected versions of this crate did substitute the array length provided by an user at compile-time multiple times.
When an impure constant expression is passed as an array length (such as a result of an impure procedural macro), this can result in the initialization of an array with uninitialized types, which in turn can allow an attacker to execute arbitrary code.
The flaw was corrected in commit d5b63f72 by making sure that array length is substituted just once.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | array-macro | ≥ 2.1.0&&< 2.1.2 | 2.1.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for array-macro. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update array-macro to 2.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-7v4j-8wvr-v55r 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 pinpoints whether GHSA-7v4j-8wvr-v55r is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-7v4j-8wvr-v55r. 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-7v4j-8wvr-v55r in your dependencies?
O3 detects GHSA-7v4j-8wvr-v55r across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.