PatchTheCVECVE-2020-35917: An issue was discovered in the pyo3 crate before 0.12.4 for Rust
CVE-2020-35917 is a medium-severity flaw (CVSS 5.5) affecting pyo3. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
An issue was discovered in the pyo3 crate before 0.12.4 for Rust. There is a reference-counting error and use-after-free in From<Py<T>>.
Why this priority
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.5 (Medium) |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 67%) |
| CISA exploited list | No |
| Weakness | CWE-416 |
| Published | 2020-12-31 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2020-35917?
pyo3: upgrade to 0.12.4. Exact commands for each OS are on this page.
Is CVE-2020-35917 being exploited?
CVE-2020-35917 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2020-35917 affect?
CVE-2020-35917 affects pyo3. Severity is medium (CVSS 5.5). An issue was discovered in the pyo3 crate before 0.12.4 for Rust. There is a reference-counting error and use-after-free in From<Py<T>>.
How urgent is CVE-2020-35917?
Priority 33/100. Public exploit reference