Vulnerability in Jpadilla Pyjwt

CVE-2024-53861

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.

EPSS: 0.008 (54.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 2.2 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2024-53861?
CVE-2024-53861 is a low-severity vulnerability in Jpadilla Pyjwt, classified under Incorrect Comparison. CVSS score: 2.2/10. Published 2024-11-29.
How severe is CVE-2024-53861?
Low severity. CVSS v3 base score is 2.2 out of 10.
Is CVE-2024-53861 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.