CVE-2024-37568 Authlib has algorithm confusion with asymmetric public keys
Attackers can bypass JWT signature verification by using asymmetric public keys for HMAC validation, allowing unauthorized access.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-37568?
CVE-2024-37568 is a high-severity authentication bypass vulnerability in n/a, published on 9 Jun 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
lepture Authlib before 1.3.1 has algorithm confusion with asymmetric public keys. Unless an algorithm is specified in a jwt.decode call, HMAC verification is allowed with any asymmetric public key. (This is similar to CVE-2022-29217 and CVE-2024-33663.)
Which versions are affected by CVE-2024-37568?
3 open source packages ship an affected version, including authlib. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
authlib PyPI | All versions | 1.3.1 |
authlib PyPI | All versions | 1.3.1 |
authlib PyPI | All versions | 1.3.1 |
Linux distribution packages (4)
python-Authlib SUSE:Linux Enterprise Module for Python 3 15 SP6 | All versions | 1.3.1-150600.3.3.1 |
python-Authlib openSUSE:Leap 15.6 | All versions | 1.3.1-150600.3.3.1 |
python-Authlib openSUSE:Tumbleweed | All versions | 1.3.1-1.1 |
python-Authlib openSUSE:Tumbleweed | All versions | 1.7.2-3.1 |
Products include Authlib Authlib.
How do I fix CVE-2024-37568?
Upgrade authlib to 1.3.1 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2024-37568 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-37568 exists.
Other vulnerabilities in n/a
- CVE-2026-27962 Authlib JWS JWK Header Injection: Signature Verification Bypass
- CVE-2026-28490 Authlib Vulnerable to JWE RSA1_5 Bleichenbacher Padding Oracle
- CVE-2026-28498 Authlib: Fail-Open Cryptographic Verification in OIDC Hash Binding
- CVE-2026-28802 Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification
- CVE-2025-61920 Authlib is vulnerable to Denial of Service via Oversized JOSE Segments
Sources
Also known as DEBIAN-CVE-2024-37568, ECHO-37cc-e0ec-bcbe, GHSA-5357-c2jx-v7qh, MGASA-2024-0238, PYSEC-2024-52, ROOT-APP-PYPI-CVE-2024-37568 and 4 more.