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Not in CISA KEV
MEDIUM severity

CVE-2024-33663 — python-jose

MEDIUM

CVE-2024-33663 is a medium-severity (CVSS 6.5) Broken Cryptographic Algorithm vulnerability in python-jose. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

python-jose algorithm confusion guard bypassed by DER-encoded public keys

Also known asCVE-2026-85394GHSA-3qf3-8w2g-rqmxGHSA-6c5p-j8vq-pqhjPYSEC-2024-232PYSEC-2026-4298
Published
Updated
Affected
1 pkg
Patched
See advisory
Exploits
None indexed
Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2024-33663.

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs24th percentile — riskier than 24% of all scored CVEsHighest risk
0.00%0.47%0.95%1.42%0.7%0.3%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
🐍python-jose

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

python-jose through 3.5.0 fails to properly validate asymmetric keys in HMAC initialization, accepting DER-encoded public keys that lack PEM armor or SSH prefixes. Attackers holding the service's public key can forge HS256 tokens that pass verification when algorithms are not explicitly restricted. This is an incomplete fix for CVE-2024-33663.

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
🐍PyPIpython-joseall versionsNo fix

Affected Products

1 product · 1 configurations
Application
python-josepython-jose_project
≤ 3.3.0
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for python-jose, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Remediation status

    The records we use list no patched version of python-jose for CVE-2024-33663. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.

  3. Mitigate without a patch

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate
ProductFixed inAdvisory
Red Hat Ansible Automation Platform 2.4 for RHEL 8automation-controller-0:4.5.10-1.el8apRHSA-2024:6428

Frequently Asked Questions

python-jose through 3.5.0 fails to properly validate asymmetric keys in HMAC initialization, accepting DER-encoded public keys that lack PEM armor or SSH prefixes. Attackers holding the service's public key can forge HS256 tokens that pass verification when algorithms are not explicitly restricted. This is an incomplete fix for CVE-2024-33663.
O3 Security · Impact-Aware SCA

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CVE-2024-33663: python-jose (Medium 6.5)