CVE-2026-114615
Authlib incomplete algorithm-confusion fix permits HMAC forgery with prefixed public keys
Description
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.
INFO
Published Date :
Oct. 22, 2026, 10:18 p.m.
Last Modified :
Oct. 29, 2026, 2:50 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update Authlib to version 1.9.0 or newer.
- Ensure key validation properly handles PEM prefixes.
- Review token verification configurations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-114615.
| URL | Resource |
|---|---|
| https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf | Patch |
| https://github.com/authlib/authlib/pull/945 | Patch |
| https://github.com/authlib/authlib/releases/tag/v1.9.0 | Release Notes |
| https://github.com/authlib/authlib/security/advisories/GHSA-7vr2-2fgp-9w7p | Exploit Mitigation Vendor Advisory |
| https://github.com/authlib/authlib/security/advisories/GHSA-7vr2-2fgp-9w7p | Exploit Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-114615 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-114615
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-114615 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-114615 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Oct. 29, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Added CPE Configuration OR *cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:* versions from (including) 1.3.1 up to (excluding) 1.9.0 Added Reference Type GitHub, Inc.: https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf Types: Patch Added Reference Type GitHub, Inc.: https://github.com/authlib/authlib/pull/945 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/authlib/authlib/releases/tag/v1.9.0 Types: Release Notes Added Reference Type CISA-ADP: https://github.com/authlib/authlib/security/advisories/GHSA-7vr2-2fgp-9w7p Types: Exploit, Mitigation, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/authlib/authlib/security/advisories/GHSA-7vr2-2fgp-9w7p Types: Exploit, Mitigation, Vendor Advisory Changed Reference Type nvd-ai-agent-0.4.0-gemma-4-31B-it: https://github.com/authlib/authlib/security/advisories/GHSA-7vr2-2fgp-9w7p Types: Exploit, Vendor Advisory nvd-ai-agent-0.4.0-gemma-4-31B-it: https://github.com/authlib/authlib/security/advisories/GHSA-7vr2-2fgp-9w7p Types: Exploit, Exploit, Mitigation, Vendor Advisory, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 29, 2026
Action Type Old Value New Value Added Reference https://github.com/authlib/authlib/security/advisories/GHSA-7vr2-2fgp-9w7p Added SSVC {'id': 'CVE-2026-114615', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-29T02:37:41.689098Z'} -
New CVE Received by [email protected]
Oct. 22, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N Added CWE CWE-347 Added CWE CWE-184 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/114xxx/CVE-2026-114615.json">CVE-2026-114615</a> Added Reference https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf Added Reference https://github.com/authlib/authlib/pull/945 Added Reference https://github.com/authlib/authlib/releases/tag/v1.9.0 Added Reference https://github.com/authlib/authlib/security/advisories/GHSA-7vr2-2fgp-9w7p