CVE-2026-102265

pyjwt: pyjwt: Denial of Service via deeply nested token headers

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Severity

Moderate

Red Hat Product Security

5.3

CVSS 3.1

Review impact separately from score.

Published · September 29, 2026

Updated · October 30, 2026

Description

A flaw was found in PyJWT. An unauthenticated remote attacker could trigger a Denial of Service (DoS) condition by supplying a specially crafted JSON Web Token (JWT) with deeply nested headers during decoding. Processing these nested structures causes an uncaught recursion error that bypasses standard error handling, leading to request-level failures and potential application crashes.

CVSS score applicability

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation

No mitigation is specified in collected source.

CVSS / CWE

CVSS 3.1 · 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CWE-248 · Uncaught Exception