CVE-2026-116672: Mcp atlassian · Authlib RFC 7592 examples omit registration-access-token client binding
Affects mcp-atlassianSource GCVE Database
Not known to be exploited · CVSS 8.8 High : upgrade to 0.23.1_2 soon.
Data as of 31 Oct 2026, 16:53 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 8.8 |
|---|
- Patch
- Available – fixed in 0.23.1_2
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 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 mcp-atlassian to 0.23.1_2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewmcp-atlassianpkg:brew/mcp-atlassianOther 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
A fix is available in mcp-atlassian version 0.23.1_2. Users should upgrade to this version or later to ensure the registration_access_token is properly bound to the client being accessed, preventing authorization bypass. Until upgraded, implementations should not rely on the provided example code for authenticate_client and check_permission without adding explicit checks that the token belongs to the client identified in the request.
Description
CVE-2026-116672 is a vulnerability in Authlib's implementation of the OAuth 2.0 Dynamic Client Registration Management Protocol (RFC 7592). The provided example code for the ClientConfigurationEndpoint fails to enforce binding between the registration_access_token and the client being accessed, allowing an attacker with any valid token and knowledge of a client_id to bypass authorization and modify or delete client registrations. This flaw arises because the example implementations do not check that the token presented belongs to the client identified in the request. The issue affects versions >=0.11.11 and <0.23.1_2 of the mcp-atlassian product and is fixed in version 0.23.1_2.
References
- github.com/authlib/authlib/security/advisories/GHSA-c73q-w75p-j82v (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-116672 (opens in a new tab)
- github.com/authlib/authlib/commit/1bd2a313492ce0a4d0571c150730907aa3fc91ff (opens in a new tab)
- github.com/authlib/authlib (opens in a new tab)
- github.com/authlib/authlib/releases/tag/v1.9.1 (opens in a new tab)