PT-2024-35959 · Pypi · Pyjwt

Fabianbadoi

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Published

2024-11-29

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Updated

2026-03-26

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CVE-2024-53861

CVSS v3.1

7.5

High

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions: pyjwt versions 2.10.0 through 2.10.0
Description: 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, where the "iss" claim checking changed from isinstance(issuer, list) to isinstance(issuer, Sequence). Since str is a Sequence, but not a list, in is also used for string comparison, resulting in if "abc" not in " abcd ": being checked instead of if "abc" != " abc ":. Signature checks are still present, so the real-world impact is likely limited to denial of service scenarios.
Recommendations: For pyjwt version 2.10.0, upgrade to version 2.10.1 to resolve the issue. As a temporary workaround, consider disabling the iss claim checking until a patch is available. Restrict access to the iss claim to minimize the risk of exploitation. Avoid using the iss claim in the affected API endpoint until the issue is resolved.

Exploit

Fix

DoS

Weakness Enumeration

Related Identifiers

CVE-2024-53861
GHSA-75C5-XW7C-P5PM
OPENSUSE-SU-2024:14540-1
SUSE-SU-2026:20879-1

Affected Products

Pyjwt