GHSA-m758-wjhj-p3jq
HIGHGHSA-m758-wjhj-p3jq is a high-severity (CVSS 7.5) CWE-248 vulnerability in wasmtime. O3 Security confirms whether GHSA-m758-wjhj-p3jq is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Wasmtime has a possible panic when lifting `flags` component value
Real-World Exposure
wasmtime🦀wasmtime🦀wasmtime🦀wasmtimeReal-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
Impact
Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val type. If bits are set outside of the set of flags the component model specifies that these bits should be ignored but Wasmtime will panic when this value is lifted. This panic only affects wasmtime's implementation of lifting into Val, not when using the flags! macro. This additionally only affects flags-typed values which are part of a WIT interface.
This has the risk of being a guest-controlled panic within the host which Wasmtime considers a DoS vector.
Patches
Wasmtime 24.0.7, 36.0.7, 42.0.2, and 43.0.1 have been issued to fix this bug. Users are recommended to update to these patched versions of Wasmtime.
Workarounds
There is no workaround for this bug if a host meets the criteria to be affected. To be affected a host must be using wasmtime::component::Val and possibly work with a flags type in the component model.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | wasmtime | all versions | 24.0.7 |
| 🦀crates.io | wasmtime | ≥ 25.0.0&&< 36.0.7 | 36.0.7 |
| 🦀crates.io | wasmtime | ≥ 37.0.0&&< 42.0.2 | 42.0.2 |
| 🦀crates.io | wasmtime | ≥ 43.0.0&&< 43.0.1 | 43.0.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wasmtime. 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 wasmtime to 24.0.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m758-wjhj-p3jq 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-m758-wjhj-p3jq 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-m758-wjhj-p3jq. 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-m758-wjhj-p3jq in your dependencies?
O3 detects GHSA-m758-wjhj-p3jq 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.