{"id":"CVE-2026-77267","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-77267","generatedAt":"2026-10-27T23:09:56.040Z","title":"A caller who can set these headers can supply an internal or metadata-service URL and cause the server to send requests to that destination, bypassing the incomplete CVE-2026-27826 remediation.","description":"MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the X-Atlassian-Jira-Url and X-Atlassian-Confluence-Url headers are processed by _process_authentication_headers and used to construct Atlassian fetchers without calling validate_url_for_ssrf. A caller who can set these headers can supply an internal or metadata-service URL and cause the server to send requests to that destination, bypassing the incomplete CVE-2026-27826 remediation. This issue is fixed in version 0.22.0.","published":"2026-09-22T18:17:19.000Z","lastModified":"2026-09-29T18:59:56.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":8.3,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-918"],"affected":["mcp-atlassian/mcp atlassian"],"epss":{"score":0.0032,"percentile":0.24818,"date":"2026-10-26","history":[{"date":"2026-09-23","score":0.00601,"percentile":0.47486}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.32%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-22T18:17:19.000Z","detail":{"score":"8.3","severity":"HIGH","publishedAt":"2026-09-22T18:17:18.803Z"},"summary":"New CVE, high severity (CVSS 8.3)."}],"references":[{"url":"https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/sooperset/mcp-atlassian/pull/1448","tags":["Issue Tracking","Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0","tags":["Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-5wf4-jqxh-8gm3","tags":["Exploit","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-5wf4-jqxh-8gm3","tags":["Exploit","Vendor Advisory"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-77267","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}