CVE-2026-114618
Authlib: Default JWT bearer grant accepts assertions for the wrong audience
Description
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, the default RFC 7523 JWTBearerGrant.get_audiences() returns an empty list, causing JWTBearerGrant.verify_claims() to require only that an aud claim exists without matching the current authorization server. An attacker holding a legitimate assertion for another service can present it to a server that shares the signing key and uses the default grant, obtaining an access token across a trust boundary. Implementations that override get_audiences() with the server's valid audience identifiers are not affected. This issue is fixed in version 1.9.0.
INFO
Published Date :
Oct. 22, 2026, 10:18 p.m.
Last Modified :
Oct. 29, 2026, 2:53 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 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Authlib to version 1.9.0.
- Ensure get_audiences() is overridden with valid audience identifiers.
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-2026-114618.
| 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-fch4-3c6x-j4gc | Exploit Vendor Advisory |
| https://github.com/authlib/authlib/security/advisories/GHSA-fch4-3c6x-j4gc | Exploit 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-2026-114618 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-2026-114618
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-2026-114618 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-114618 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 CPE Configuration OR *cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:* versions 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-fch4-3c6x-j4gc Types: Exploit, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/authlib/authlib/security/advisories/GHSA-fch4-3c6x-j4gc Types: Exploit, 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-fch4-3c6x-j4gc Added SSVC {'id': 'CVE-2026-114618', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-29T12:28:44.727870Z'} -
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. Prior to 1.9.0, the default RFC 7523 JWTBearerGrant.get_audiences() returns an empty list, causing JWTBearerGrant.verify_claims() to require only that an aud claim exists without matching the current authorization server. An attacker holding a legitimate assertion for another service can present it to a server that shares the signing key and uses the default grant, obtaining an access token across a trust boundary. Implementations that override get_audiences() with the server's valid audience identifiers are not affected. This issue is fixed in version 1.9.0. Added CVSS V3.1 AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N Added CWE CWE-287 Added CWE CWE-1188 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/114xxx/CVE-2026-114618.json">CVE-2026-114618</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-fch4-3c6x-j4gc