6.8
MEDIUM CVSS 3.1
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. 22, 2026, 10:18 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-114618 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Authlib authlib
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM MITRE-CVE
CVSS 3.1 MEDIUM [email protected]
Solution
Update Authlib to version 1.9.0 or later to fix JWT assertion validation.
  • Update Authlib to version 1.9.0.
  • Ensure get_audiences() is overridden with valid audience identifiers.
References to Advisories, Solutions, and Tools
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:

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.

  • 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
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.