{"id":"CVE-2026-77261","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-77261","generatedAt":"2026-10-28T01:45:25.209Z","title":"If an attacker-controlled or compromised configured Atlassian instance returns a redirect to an internal address, those sessions can follow the redirect without revalidating its destination.","description":"MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, _make_ssrf_safe_hook is omitted from JiraFetcher and ConfluenceFetcher sessions created through the basic-auth and oauth_pat branches. If an attacker-controlled or compromised configured Atlassian instance returns a redirect to an internal address, those sessions can follow the redirect without revalidating its destination. This issue is fixed in version 0.22.0.","published":"2026-09-22T18:17:18.000Z","lastModified":"2026-09-25T17:36:33.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":8.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N"},"cwe":["CWE-918"],"affected":["mcp-atlassian/mcp atlassian"],"epss":{"score":0.00373,"percentile":0.31007,"date":"2026-10-26","history":[{"date":"2026-09-23","score":0.00323,"percentile":0.25547}]},"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 (0.37%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"scored","label":"Newly scored","at":"2026-09-25T18:15:06.000Z","detail":{"from":"7.1","score":"8.5","severity":"HIGH","fromSeverity":"HIGH"},"summary":"Now scored CVSS 8.5 HIGH (was 7.1)."},{"kind":"new","label":"New CVE","at":"2026-09-22T18:17:18.000Z","detail":{"score":"7.1","severity":"HIGH","publishedAt":"2026-09-22T18:17:18.497Z"},"summary":"New CVE, high severity (CVSS 8.5)."}],"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":["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-6529-c226-h328","tags":["Exploit","Vendor Advisory"],"source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-77261","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."}