CVE-2026-114615

What it is

Authlib is a Python library which builds OAuth and OpenID Connect servers. From 1.3.1 until 1.9.0, OctKey.import_key() checks asymmetric-key markers only at byte zero while Authlib's PEM loaders accept leading whitespace, comments, or a byte-order mark. In deployments that use the documented mixed algorithm registry and already configure verification with PEM or certificate bytes containing such a prefix, an unauthenticated attacker who knows those same public-key bytes can use them as an HMAC secret and forge HS256 tokens with arbitrary identity or authorization claims. This is a bypass of the remediation for CVE-2024-37568. The module-level jwt object reaches OctKey.import_key() in authlib/jose/rfc7518/oct_key.py, where POSSIBLE_UNSAFE_KEYS fails to identify prefixed asymmetric key material. This issue is fixed in version 1.9.0.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-10-21 20:34 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-10-22 22:18 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-10-29 14:50 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 7.4 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-10-22 22:18 UTC

Last modified

2026-10-29 14:50 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-184

Record status

Analyzed

Affected

• Authlib < 1.9.0

Attack profile CVSS 3.1 · 7.4

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-114615.md and follow it. Check whether this project is affected by CVE-2026-114615. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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