Description
typed_ast 1.3.0 and 1.3.1 has a handle_keywordonly_args out-of-bounds read. An attacker with the ability to cause a Python interpreter to parse Python source (but not necessarily execute it) may be able to crash the interpreter process. This could be a concern, for example, in a web-based service that parses (but does not execute) Python code. (This issue also affected certain Python 3.8.0-alpha prereleases.)
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 12 | python3-typed-ast | 1.4.0-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | python3-typed-ast | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP1 | python-typed-ast | 1.3.1-bp151.2.6.1 | openSUSE-SU-2020:0609-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.1 | python-typed-ast | 1.3.1-lp151.2.6.1 | openSUSE-SU-2020:0567-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | typed-ast | >= 1.3.0, < 1.3.2 | 1.3.2 | GHSA-m3jw-62m7-jjcm |
| PyPI | typed-ast | < 1.3.2 | 1.3.2 | PYSEC-2019-130 |
Advisories 2
- openSUSE-SU-2020:0567-1 Security update for python-typed-ast SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0609-1 Security update for python-typed-ast SUSE / openSUSE Security Updates · May 7, 2025
References
- https://github.com/python/typed_ast/commit/156afcb26c198e162504a57caddfe0acd9ed7dce
- https://github.com/python/cpython/commit/dcfcd146f8e6fc5c2fc16a4c192a0c5f5ca8c53c
- https://github.com/python/cpython/commit/a4d78362397fc3bced6ea80fbc7b5f4827aec55e
- https://github.com/python/typed_ast/commit/dc317ac9cff859aa84eeabe03fb5004982545b3b
- https://bugs.python.org/issue36495
- FEDORA-2020-9b3dabc21c vendor-advisory