Authlib: Prior to 1.9.0, OpenIDImplicitGrant.validate_authorization_request() checks the client-controlled raw
Affects authlibSource GCVE Database
Not known to be exploited · CVSS 4.6 Medium : upgrade to 1.9.0 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 4.6 |
|---|
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.9.0
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 22 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 Oct 2026.
What to do
Upgrade authlib to 1.9.0.
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
PyPIauthlibpkg:pypi/authlibOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to Authlib version 1.9.0 or later, where the issue is fixed. The patch changes the validation to check the filtered request.scope instead of the client-controlled raw request.payload.scope. No other mitigation is indicated.
Description
Authlib versions prior to 1.9.0 contain a vulnerability in the OpenIDImplicitGrant.validate_authorization_request() method where the client-controlled raw request payload scope is checked instead of the filtered allowed scopes. This allows a registered client permitted an ID token response type but not the openid scope to add openid to the request, obtain user consent, and receive a signed ID token with user subject and profile claims. The issue is fixed in version 1.9.0.
References
- github.com/authlib/authlib/releases/tag/v1.9.0 (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/security/advisories/GHSA-q686-2qmg-hqc7 (opens in a new tab)