PyJWT: Unauthenticated RecursionError DoS in pre-verification payload parse (PyJWKClient.get_signing_key_from_jwt / verify_signature=False)

SummaryPyJWKClient.getsigningkeyfromjwttoken — the first step of the JWKSverification flow documented in docs/usage.rst — must decode a token'spayload before its signature can be checked, viajwt.apijwt.decodecompletetoken, options="verifysignature": False.That call parses the payload with...

360solutions-bc-mcp (>=0.5.3, <=0.5.7), acapy-agent (>=1.5.1rc0, <=1.7.0) +310 more potentially affected by CVE-2026-103001 via pyjwt (>=2.11.0, <=2.13.0)

pyjwt PYPI version =2.11.0, =0.5.3, =1.5.1rc0, =0.1.8, =0.0.116, =1.5.0a9, =0.7.0rc9, =1.405.15, =26.2.0, =4.1.102, =1.2.1, =0.0.17, =0.23.0, =0.51.0, =0.62.0 and more Source cves: CVE-2026-103001 Source advisory: OSV:PYSEC-2026-4146...

10xscale-agentflow-cli (0.1.5), 360solutions-bc-mcp (>=0.5.3, <=0.5.7) +1693 more potentially affected by CVE-2026-101918 via pyjwt (>=2.0.0a2, <=2.14.0)

pyjwt PYPI version =2.0.0a2, =0.5.3, =2.3.0, =0.1.0, =1.0.0, =1.8.26, =1.1.0rc1, =1.0.1, =0.1.0.post1, =0.1.5, =2.3.10rc8, =0.0.9rc17, =1.2.0, =1.2.1 - adminui 1.5.2 and more Source cves: CVE-2026-101918 Source advisory: OSV:PYSEC-2026-4141...

PYSEC-2026-4151 PyJWT accepts public JWK containers as HMAC secrets

Summary PyJWT 2.13.0 contains an incomplete defense against algorithm confusion when an application mixes symmetric and asymmetric algorithms in one verification path. A public RSA, EC, or OKP JWK can be accepted as an HMAC secret when it is wrapped in a JWKS object, nested in an array, or...

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...

PYSEC-2026-4152 PyJWT: Malformed RSA JWK aborts parsing of an entire JWK Set

Summary A malformed RSA JWK inside a JWK Set aborts parsing of the entire set instead of being skipped, because RSAAlgorithm.fromjwk can raise a plain ValueError that isn't caught by PyJWKSet's per-key error-skipping logic. Affected component / version - Package: PyJWT PyPI, ecosystem pip - Files...

PyJWT: PyJWKClient still amplifies unauthenticated JWKS fetches on unknown kid values (incomplete fix of CVE-2026-48524)

SummaryCVE-2026-48524 GHSA-fhv5-28vv-h8m8, "PyJWKClient unbounded JWKS endpoint requests via attacker-controlled kid values DoS" was fixed in 2.13.0 by stopping fetchdata from clearing the cache on a fetch error. That closed one amplification path but did not add the mitigation the advisory's tit...

PyJWT BOM Bypass

Affected Package- Package: PyJWT pyjwt on PyPI- Repository: https://www.google.com/url?q=https://github.com/jpadilla/pyjwt=gmail=1781794518474000=E- Affected version: 2.13.0- Vulnerability class: Algorithm confusion / patch bypass--- Root CausePyJWT 2.13.0 introduced a guard in...

PyJWT: Public keys in DER form are accepted as HMAC secrets, bypassing the CVE-2022-29217 guard

SummaryHMACAlgorithm.preparekey blocks asymmetric keys from being used as HMAC secrets by searching for text markers only. It looks for -----BEGIN and for an ssh- prefix. The same key in DER form is binary ASN.1 and has neither marker, so it passes the check and is used as an HMAC secret.An...

PyJWT: Malformed RSA JWK aborts parsing of an entire JWK Set

SummaryA malformed RSA JWK inside a JWK Set aborts parsing of the entire set instead of being skipped, because RSAAlgorithm.fromjwk can raise a plain ValueError that isn't caught by PyJWKSet's per-key error-skipping logic. Affected component / version- Package: PyJWT PyPI, ecosystem pip- Files:...

aap-client-python (>=0.1.1, <=0.1.3), gcb-web-auth (>=0.6.0, <=2.0.0) +4 more potentially affected by CVE-2026-102269 via pyjwt (1.5.2)

pyjwt PYPI version 1.5.2 is affected by a known vulnerability. The following packages have a transitive dependency on pyjwt and may be impacted: - aap-client-python =0.1.1, =0.6.0, =0.2775.0, =0.3.0, =0.0.1, =4.0.0, =4.0.1 Source cves: CVE-2026-102269 Source advisory: OSV:PYSEC-2026-4147...

PYSEC-2026-4142 PyJWT: Uncaught RecursionError in jwt.decode() on deeply nested token header

Package pyjwt PyPI Affected versions tested & verified on: 2.13.0. Every version whose PyJWS.load translates only ValueError is affected Description PyJWS.looad jwt/apijws.py:337 splits the compact token, base64url decodes the header segment and hands it to json.loads before verifysignature runs...

PyJWT: Uncaught RecursionError in jwt.decode() on deeply nested token header

Packagepyjwt PyPI Affected versionstested & verified on: 2.13.0. Every version whose PyJWS.load translates only ValueError is affected DescriptionPyJWS.looad jwt/apijws.py:337 splits the compact token, base64url decodes the header segment and hands it to json.loads before verifysignature runs. Th...

PYSEC-2026-4144 PyJWT: PyJWKClient follows redirects when fetching JWKS

Summary PyJWT 2.13.0 PyJWKClient followed HTTP redirects while fetching a JWKS, without validating the redirect destination. A configured trusted endpoint could therefore redirect the client to a different host. Impact When an application uses PyJWKClient with caller-supplied request headers and ...

PyJWT: PyJWKClient follows redirects when fetching JWKS

SummaryPyJWT 2.13.0 PyJWKClient followed HTTP redirects while fetching a JWKS,without validating the redirect destination. A configured trusted endpointcould therefore redirect the client to a different host. ImpactWhen an application uses PyJWKClient with caller-supplied request headers andan...

PYSEC-2026-4145 PyJWT: Asymmetric-PEM detection bypass: whitespace/line-ending-mutated public keys skip the HS/asymmetric confusion guard

Prerequisites both conditions must hold; both are deployment properties, not attacker-controlled at request time: - The jwt.decode allow-list mixes an HMAC algorithm with an asymmetric one, e.g. algorithms="ES256", "HS256" the RFC 8725 footgun the guard exists to backstop. - The verification key ...

atlassian-jwt-auth (>=2.0.0, <=2.6.0), clink (>=0.10.0, <=0.23.0) +7 more potentially affected by CVE-2026-101917 via pyjwt (1.4.0)

pyjwt PYPI version 1.4.0 is affected by a known vulnerability. The following packages have a transitive dependency on pyjwt and may be impacted: - atlassian-jwt-auth =2.0.0, =0.10.0, =0.0.1.dev1, =0.0.1.dev3, =0.4.0, =3.1.0, =1.1.0, =0.8.0, =0.9.0 Source cves: CVE-2026-101917 Source advisory:...

more-jwtauth (0.7.0) potentially affected by CVE-2026-102267 via pyjwt (1.4.1)

pyjwt PYPI version 1.4.1 is affected by a known vulnerability. The following packages have a transitive dependency on pyjwt and may be impacted: - more-jwtauth 0.7.0 Source cves: CVE-2026-102267 Source advisory: OSV:PYSEC-2026-4144...

more-jwtauth (0.7.0) potentially affected by CVE-2026-102269 via pyjwt (1.4.1)

pyjwt PYPI version 1.4.1 is affected by a known vulnerability. The following packages have a transitive dependency on pyjwt and may be impacted: - more-jwtauth 0.7.0 Source cves: CVE-2026-102269 Source advisory: OSV:PYSEC-2026-4147...