CVE-2026-77272
mediumMCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira).
Vendor / product: Mcp-atlassian — mcp atlassian
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the OAuth error query parameter is passed to CallbackHandler._send_response in oauth_setup.py and interpolated into an HTML page without escaping. A crafted authorization callback can inject markup or script that executes in the browser of a user completing the OAuth flow. This issue is fixed in version 0.22.0.
CVSS
6.1
6.1 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Severity source: NVD CVSS v3.1 (nvd@nist.gov)
Timeline (UTC)
Published: 2026-09-22 19:16
Modified: 2026-09-28 13:10
NVD status: Analyzed
Last synced 3 days ago
Verified against the source API 2026-10-27 06:55 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
mcp-atlassian / mcp_atlassian <0.22.0
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Patch / mitigation: https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
Patch / mitigation: https://github.com/sooperset/mcp-atlassian/pull/1448
References
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 security-advisories@github.com
- https://github.com/sooperset/mcp-atlassian/pull/1448 security-advisories@github.com
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 security-advisories@github.com
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-g2r2-3j32-j27x security-advisories@github.com
Data sources
NVD CVE API 2.0 — fetched 2026-10-27 06:55 UTC · record ↗