GHSA-36hh-v3qg-5jq4
GHSA-36hh-v3qg-5jq4 is a remote code execution vulnerability in pyo3. O3 Security confirms whether GHSA-36hh-v3qg-5jq4 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
PyO3 has an Out-of-bounds Read in `nth` / `nth_back` for `PyList` and `PyTuple` iterators
Blast Radius
pyo3Real-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
PyO3 0.24.0 added optimized implementations of Iterator::nth and DoubleEndedIterator::nth_back for the BoundListIterator and BoundTupleIterator types. These implementations computed the target index using unchecked usize addition (index + n) before bounds-checking against the sequence length, then read the element via get_item_unchecked.
In nth methods, a sufficiently large n (combined with a non-zero internal index) could cause the addition to overflow and wrap around, producing a small "target index" that passed the bounds check and enabling reads at the front of the list or tuple of elements previously yielded by the iterator.
In nth_back methods, a sufficiently large n could cause underflow in a similar fashion, however would instead allow reads of arbitrary memory past the end of the list or tuple storage.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | pyo3 | all versions | 0.29.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pyo3. 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 pyo3 to 0.29.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-36hh-v3qg-5jq4 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-36hh-v3qg-5jq4 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-36hh-v3qg-5jq4. 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-36hh-v3qg-5jq4 in your dependencies?
O3 detects GHSA-36hh-v3qg-5jq4 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.