Authentication bypass in mcp-atlassian HTTP transport
- Product
- mcp-atlassian
- CVE
- CVE-2026-77244
- Affected
- mcp-atlassian < 0.22.0
- Fixed in
- 0.22.0
Last verified against sources: October 26, 2026
Am I affected?
mcp-atlassian: affected mcp-atlassian < 0.22.0. Fixed in 0.22.0.
- Check your version: run
pip show mcp-atlassian. Versions < 0.22.0 of mcp-atlassian are affected. [1]
What to do now
- Upgrade to the fixed version: run
pip install --upgrade "mcp-atlassian>=0.22.0"(first patched version 0.22.0). [1] - Do not expose the HTTP transport without authentication. [1]
General practice, not from the source: if the affected software could read tokens or credentials, rotate them after upgrading; pin versions and review changes before updating tools your agents run.
What happened
- The token checker AtlassianOpaqueTokenVerifier accepts any non-empty text as a valid token. [1]
- By default the OAuth proxy login check is turned off, so the HTTP transport takes requests with no login. [1]
- When a request has no Authorization header, the middleware does not reject it. [1]
- With no user token, the Jira and Confluence fetchers fall back to the server's own environment credentials. [1]
Impact
- Anyone who can reach the HTTP transport can use the server with no credentials at all. [1]
- The attacker gets full read and write access to the operator's Jira and Confluence. [1]
- Every API call is signed with the operator's token, so Atlassian's logs name the operator. [1]
- The attacker can create Jira webhooks, automation rules, or Confluence integrations that outlive the session. [1]
What was done
- The package is patched in version 0.22.0. [1]
Sources
- GHSA-wrhw-j3f9-8vc6 — GitHub Advisory Database
Every statement above was checked against these sources before publishing. Spotted an error? Tell us and we will correct it with a dated note.
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[CVE-2026-77244] Authentication bypass in mcp-atlassian HTTP transport
Product: mcp-atlassian | Affected: mcp-atlassian < 0.22.0 | Fixed in: 0.22.0
Summary: The token checker AtlassianOpaqueTokenVerifier accepts any non-empty text as a valid token.
Source & remediation on AgentArmorHQ: https://agentarmorhq.com/incidents/2026/09/cve-2026-77244-mcp-atlassianCorrections
Report an error or request a correction. We review requests within 5 business days and add a dated correction note.
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