Python authlib: Prior to 1.9.0, the default RFC 7523 JWTBearerGrant.get_audiences() returns an empty list, causing
Affects python-authlibSource GCVE Database
Not known to be exploited · CVSS 6.8 Medium · fixed in 1.9.0 : update python-authlib when convenient.
Data as of 28 Oct 2026, 22:31 UTC
- Patch
- Available – fixed in 1.9.0
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 22 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10python-authlibpkg:deb/ubuntu/python-authlib?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu Pro 26.04 LTSpython-authlibpkg:deb/ubuntu/python-authlib?arch=source&distro=esm-apps/resoluteOther threats | Affected
| Fixed in– |
Ubuntu Pro 24.04 LTSpython-authlibpkg:deb/ubuntu/python-authlib?arch=source&distro=esm-apps/nobleOther threats | Affected
| Fixed in– |
Ubuntu Pro 22.04 LTSpython-authlibpkg:deb/ubuntu/python-authlib?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2026-114618 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-114618 (opens in a new tab)
- github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf (opens in a new tab)
- github.com/authlib/authlib/pull/945 (opens in a new tab)
- github.com/authlib/authlib/releases/tag/v1.9.0 (opens in a new tab)
- github.com/authlib/authlib/security/advisories/GHSA-fch4-3c6x-j4gc (opens in a new tab)