cve-2026-102268-poc

CVE-2026-102268 — PyJWT Asymmetric-PEM Detection Bypass Exploitability analysis result: the root cause is confirmed and end-to-end exploitation is reproducible. A whitespace-mutated PEM public key bypasses PyJWT's ispemformat guard and is accepted as a valid HMAC secret, enabling full HS256 token...

Exploit for CVE-2026-102268

CVE-2026-102268 — PyJWT Asymmetric-PEM Detection Bypass E...

PyJWT jwt/utils.py Function Disclosure

The vulnerability of the ispemformat function in the jwt/utils.py library of PyJWT is related to errors in the verification of the cryptographic signature. Exploiting this vulnerability could allow an attacker to bypass existing security mechanisms and disclose sensitive information...

PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.

SummaryThere is a Re-DoS vulnerability in the ispemformat function which results in a intesive CPU usage if an attacker is been able to provide a custom certificate. DetailsThe problem is that the lazy quantifier .+? will always first try to match as little as possible until it finds a ---- END...

PYSEC-2026-4148 PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.

Summary There is a Re-DoS vulnerability in the ispemformat function which results in a intesive CPU usage if an attacker is been able to provide a custom certificate. Details The problem is that the lazy quantifier .+? will always first try to match as little as possible until it finds a ---- END...

EUVD-2026-88537

PyJWT: ReDoS vulnerability when calling the ispemformat function...

PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.

Summary There is a Re-DoS vulnerability in the ispemformat function which results in a intesive CPU usage if an attacker is been able to provide a custom certificate. Details The problem is that the lazy quantifier .+? will always first try to match as little as possible until it finds a ---- END...

GHSA-JWRC-G2Q2-PQ5P PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.

Summary There is a Re-DoS vulnerability in the ispemformat function which results in a intesive CPU usage if an attacker is been able to provide a custom certificate. Details The problem is that the lazy quantifier .+? will always first try to match as little as possible until it finds a ---- END...

Linux Distros Unpatched Vulnerability : CVE-2026-102270

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT ispemformat is affected because lazy PEM regular expression backtracks...

Linux Distros Unpatched Vulnerability : CVE-2026-102268

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, ispemformat in jwt/utils.py is affected because ispemformat does not recognize...

SUSE CVE-2026-102268

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, ispemformat in jwt/utils.py is affected because ispemformat does not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and...

SUSE CVE-2026-102270

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT ispemformat is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, ispemforma...

CVE-2026-102270

A flaw was found in PyJWT. An attacker can cause a Denial of Service DoS by providing crafted certificate-like input containing repeated start markers without matching end markers. This malformed input triggers excessive regular expression backtracking during validation in the ispemformat functio...

Regular Expression Denial of Service (ReDoS)

Overview Affected versions of this package are vulnerable to Regular Expression Denial of Service ReDoS via ispemformat in jwt/utils.py, which previously used a regex PEMRE that accepted PEM formatting variants recognised by the underlying cryptography loader but not explicitly validated by pyjwt...

Improper Verification of Cryptographic Signature

Overview PyJWT is a Python implementation of RFC 7519. Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature via ispemformat in jwt/utils.py, which fails to recognize certain loader-accepted PEM formatting variants as valid PEM. The fix for...

DEBIAN-CVE-2026-102270

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT ispemformat is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, ispemforma...

CVE-2026-102270

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT ispemformat is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, ispemforma...

DEBIAN-CVE-2026-102268

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, ispemformat in jwt/utils.py is affected because ispemformat does not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and...

CVE-2026-102268

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, ispemformat in jwt/utils.py is affected because ispemformat does not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and...

AZL-104988 CVE-2026-102270 affecting package python-jwt 2.13.0-1

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT ispemformat is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, ispemforma...