CVE-2024-53861
Published: December 4, 2024Last modified: June 25, 2025
Description
pyjwt is a JSON Web Token implementation in Python. An incorrect string comparison is run for `iss` checking, resulting in `"acb"` being accepted for `"_abc_"`. This is a bug introduced in version 2.10.0: checking the "iss" claim changed from `isinstance(issuer, list)` to `isinstance(issuer, Sequence)`. Since str is a Sequnce, but not a list, `in` is also used for string comparison. This results in `if "abc" not in "__abcd__":` being checked instead of `if "abc" != "__abc__":`. Signature checks are still present so real world impact is likely limited to denial of service scenarios. This issue has been patched in version 2.10.1. All users are advised to upgrade. There are no known workarounds for this vulnerability.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 2.2 |
| Attack Vector | NETWORK |
| Attack complexity | HIGH |
| Privileges required | HIGH |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | LOW |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N |
Notes
This bug was introduced in 2.10 and was patched in 2.10.1, but we don't have the version 2.10 of this package
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | Stream | py3-jwt | Not affected (2.8.0-r1) |
References
- https://github.com/jpadilla/pyjwt/commit/1570e708672aa9036bc772476beae8bfa48f4131#diff-6893ad4a1c5a36b8af3028db8c8bc3b62418149843fc382faf901eaab008e380R366
- https://github.com/jpadilla/pyjwt/commit/33022c25525c1020869c71ce2a4109e44ae4ced1
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-75c5-xw7c-p5pm