CVE-2026-102273

highpriority · track · 0EPSS 0.002 · 7 %ileDEFRUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.18% (7th) EPSS
CVSS 7.4 · high
Is it mine?
7 products
Check your exposure
Who says so?
4 sources
osv · cert_bund · nvd · certfr

EPSS · scored 2026-10-27

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because HMAC key guard only recognizes top-level public JWK forms and misses container representations. This occurs when an application allows HMAC and asymmetric algorithms and passes a public JWK container as the raw key. As a result, public asymmetric key material is accepted as the HMAC secret. Consequently, an attacker who knows the public key can forge a token with arbitrary authenticated claims. This issue is fixed in version 2.14.0.

01

cvss

Technical severity, 0–10. One row per scoring source.

7.4
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.8–7.4

v3.17.4highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondary · security-advisories@github.comexploitability 2.2 · impact 5.2
v3.17.4highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondary · OSV
v3.16.8mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

affected products (7)

Products and version ranges known to be affected.

05

advisories (4)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-4111Red Hat Ansible Automation Platform: Mehrere SchwachstellenDeutsch2026-10-21csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Red Hat Ansible Automation Platform ausnutzen, um beliebigen Code mit Benutzer- oder Anwendungsrechten auszuführen, gültige kryptografische Token zu fälschen, die Authentifizierung zu umgehen, erweiterte Rechte zu erlangen, Denial-of-Service-Zustände auszulösen sowie Daten zu manipulieren oder offenzulegen.

  • GHSA-w2cx-738m-mc7wPyJWT accepts public JWK containers as HMAC secrets2026-09-29ghsa · osvUS

    ### 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 represented in another container form that does not expose a top-level `kty` member. ### Impact An attacker who knows the public key material can forge HS256/HS384/HS512 tokens if the application simultaneously: * allows both HS* and asymmetric algorithms; * passes raw public JWK/JWKS JSON as `key=`; and * uses that same value as the HMAC secret. This can allow forged JWT claims in affected application configurations. The issue does not affect applications that keep symmetric and asymmetric verification paths separate and follow PyJWT's algorithm-selection guidance. ### Fix status The fix is on `master` in commit `801cd12` (`fix: reject public JWK container HMAC keys`). `HMACAlgorithm.prepare_key` now rejects public JWK members found in objects, arrays, nested containers, BOM/UTF variants, and recursion-limit inputs. It also recognizes escaped JSON member names without treating ordinary string values as JWKs. Ordinary JSON secrets remain accepted byte-for-byte. The change was tested with focused regression tests and the full local tox matrix. Available Python 3.9, 3.12, and 3.13 crypto/no-crypto suites, mypy, package metadata, and coverage passed; unavailable interpreters were skipped by the project configuration. A fresh independent Astra/max security review accepted the final diff with no blocking findings. The affected range is `= 2.13.0`. The fix is on the unreleased development branch; the patched version will be recorded when a released 2.x version containing the fix is available. This advisory is being moved to draft pending that release. ### Reporter credit Credit: Charles Vosburgh / Trilobyte. ### Original report The original report and reproduction package are retained in the private advisory record. ## Maintainer update — 2026-09-11 The verified fix for this advisory is included in PyJWT 2.14.0, released on 2026-09-11 and available on PyPI. PyJWT 2.14.0 is the first release containing the fix. This advisory is now published with 2.14.0 recorded as the patched version.

  • CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
  • PYSEC-2026-4151PyJWT accepts public JWK containers as HMAC secrets2026-10-01vendor · osvUS

    ### 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 represented in another container form that does not expose a top-level `kty` member. ### Impact An attacker who knows the public key material can forge HS256/HS384/HS512 tokens if the application simultaneously: * allows both HS* and asymmetric algorithms; * passes raw public JWK/JWKS JSON as `key=`; and * uses that same value as the HMAC secret. This can allow forged JWT claims in affected application configurations. The issue does not affect applications that keep symmetric and asymmetric verification paths separate and follow PyJWT's algorithm-selection guidance. ### Fix status The fix is on `master` in commit `801cd12` (`fix: reject public JWK container HMAC keys`). `HMACAlgorithm.prepare_key` now rejects public JWK members found in objects, arrays, nested containers, BOM/UTF variants, and recursion-limit inputs. It also recognizes escaped JSON member names without treating ordinary string values as JWKs. Ordinary JSON secrets remain accepted byte-for-byte. The change was tested with focused regression tests and the full local tox matrix. Available Python 3.9, 3.12, and 3.13 crypto/no-crypto suites, mypy, package metadata, and coverage passed; unavailable interpreters were skipped by the project configuration. A fresh independent Astra/max security review accepted the final diff with no blocking findings. The affected range is `= 2.13.0`. The fix is on the unreleased development branch; the patched version will be recorded when a released 2.x version containing the fix is available. This advisory is being moved to draft pending that release. ### Reporter credit Credit: Charles Vosburgh / Trilobyte. ### Original report The original report and reproduction package are retained in the private advisory record. ## Maintainer update — 2026-09-11 The verified fix for this advisory is included in PyJWT 2.14.0, released on 2026-09-11 and available on PyPI. PyJWT 2.14.0 is the first release containing the fix. This advisory is now published with 2.14.0 recorded as the patched version.

06

also known as (2)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

published 2026-09-28modified 2026-10-06
08

references (3) nvd

External citations — patches, advisories, analysis.

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