Webargs mishandles concurrent JSON parsing
An issue was discovered in webargs before 5.1.3, as used with marshmallow and other products. JSON parsing uses a short-lived cache to store the parsed JSON body. This cache is not thread-safe, meaning that incorrect JSON payloads could have been parsed for concurrent requests.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | webargs | < 5.1.3 | 5.1.3 |
References
- https://webargs.readthedocs.io/en/latest/changelog.html
- https://github.com/marshmallow-code/webargs/issues/371
- https://github.com/advisories/GHSA-8554-jxcw-454q
- https://nvd.nist.gov/vuln/detail/CVE-2019-9710
- https://github.com/marshmallow-code/webargs/pull/373
- https://github.com/marshmallow-code/webargs/commit/716bd8d1f24c84aaf99170efaa17d1d34206f6c0
- https://github.com/marshmallow-code/webargs
- https://github.com/pypa/advisory-database/tree/main/vulns/webargs/PYSEC-2019-139.yaml
- https://webargs.readthedocs.io/en/latest/changelog.html#id24
- CVSS vector
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H- Weakness (CWE)
CWE-362- Platform
- Python (PyPI)
- Package
webargs- Disclosed
- 12.03.2019
- Updated
- 11.10.2026 12:19
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2019-139 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-8554-jxcw-454q - CC BY 4.0
Vulnerability history: webargs
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 03.2019 01.2020
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 2
Disclosures per year
- 2019: 1
- 2020: 1
- 2021: 0
- 2022: 0
- 2023: 0
- 2024: 0
- 2025: 0
- 2026: 0
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Webargs mishandles concurrent JSON parsing this entry
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