NIST deprecates RSA-2048 from 2030. Find every one of them before attackers do.
🦀 crates.io
Not in CISA KEV

PyO3 Risk of buffer overflow in `PyString::from_object`GHSA-pph8-gcv7-4qj5

Fix: PyO3/pyo3#5008

GHSA-pph8-gcv7-4qj5 is a remote code execution vulnerability in pyo3. A fix is available for pyo3 — see the affected versions and patch details below.

Also known asRUSTSEC-2025-0020
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 10, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected
🦀pyo3

Real-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

PyString::from_object took &str arguments and forwarded them directly to the Python C API without checking for terminating nul bytes. This could lead the Python interpreter to read beyond the end of the &str data and potentially leak contents of the out-of-bounds read (by raising a Python exception containing a copy of the data including the overflow).

In PyO3 0.24.1 this function will now allocate a CString to guarantee a terminating nul bytes. PyO3 0.25 will likely offer an alternative API which takes &CStr arguments.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🦀crates.iopyo3≥ 0.1.0&&< 0.24.10.24.1cargo update -p pyo3 --precise 0.24.1

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pyo3, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update pyo3 to 0.24.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pph8-gcv7-4qj5 is resolved across your whole dependency graph.

  3. Workarounds

    Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Frequently Asked Questions

`PyString::from_object` took `&str` arguments and forwarded them directly to the Python C API without checking for terminating nul bytes. This could lead the Python interpreter to read beyond the end of the `&str` data and potentially leak contents of the out-of-bounds read (by raising a Python exception containing a copy of the data including the overflow). In PyO3 0.24.1 this function will now allocate a `CString` to guarantee a terminating nul bytes. PyO3 0.25 will likely offer an alternative API which takes `&CStr` arguments.
O3 Security · Impact-Aware SCA

Is GHSA-pph8-gcv7-4qj5 in your dependencies?

Find it across crates.io, including transitive dependencies.

Scan my dependencies How O3 SCA works
PyO3 Risk of buffer overflow in `PyString::from_object`