{"id":"CVE-2021-26073","aliases":["EUVD-2021-12896","GHSA-4v96-m8xv-x83v"],"status":"published","title":"Broken Authentication in Atlassian Connect Express","description":"Broken Authentication in Atlassian Connect Express (ACE) from version 3.0.2 before version 6.6.0: Atlassian Connect Express is a Node.js package for building Atlassian Connect apps. Authentication between Atlassian products and the Atlassian Connect Express app occurs with a server-to-server JWT or a context JWT. Atlassian Connect Express versions from 3.0.2 before 6.6.0 erroneously accept context JWTs in lifecycle endpoints (such as installation) where only server-to-server JWTs should be accepted, permitting an attacker to send authenticated re-installation events to an app.","severity":{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.00948,"percentile":0.61471,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-287","CWE-863"],"published":"2021-04-16T03:00:19Z","modified":"2026-06-17T03:42:48Z","fixes":[{"ecosystem":"npm","package":"atlassian-connect-express","fixed_in":["6.6.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"atlassian-connect-express","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.2"},{"fixed":"6.6.0"}]}]},{"source":"osv","ecosystem":"npm","package":"atlassian-connect-express","ranges":[{"type":"SEMVER","events":[{"introduced":"3.0.2"},{"fixed":"6.6.0"}]}]}],"products":[{"vendor":"atlassian","product":"atlassian connect express (ace)"},{"vendor":"atlassian","product":"connect_express"}],"references":[{"url":"https://confluence.atlassian.com/pages/viewpage.action?pageId=1051986099","tags":["x_refsource_MISC","x_transferred","Vendor Advisory","web"]},{"url":"https://community.developer.atlassian.com/t/action-required-atlassian-connect-vulnerability-a%5B%E2%80%A6%5Dypass-of-app-qsh-verification-via-context-jwts/47072","tags":["x_refsource_MISC","x_transferred","web"]},{"url":"https://security.netapp.com/advisory/ntap-20210604-0004/","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26073","tags":["advisory"]},{"url":"https://security.netapp.com/advisory/ntap-20210604-0004","tags":["web"]},{"url":"https://github.com/advisories/GHSA-4v96-m8xv-x83v"},{"url":"http://bitbucket.org/atlassian/atlassian-connect-express","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2021-26073","description":"Broken Authentication in Atlassian Connect Express (ACE) from version 3.0.2 before version 6.6.0: Atlassian Connect Express is a Node.js package for building Atlassian Connect apps. Authentication between Atlassian products and the Atlassian Connect Express app occurs with a server-to-server JWT or a context JWT. Atlassian Connect Express versions from 3.0.2 before 6.6.0 erroneously accept context JWTs in lifecycle endpoints (such as installation) where only server-to-server JWTs should be accepted, permitting an attacker to send authenticated re-installation events to an app.","status":"published","published":"2021-04-16T03:00:19.147Z","modified":"2025-02-12T20:46:54.554Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N","level":"high","assessor":"adp"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:32:57.033395Z"}],"euvd":[{"id":"EUVD-2021-12896","description":"Broken Authentication in Atlassian Connect Express (ACE) from version 3.0.2 before version 6.6.0: Atlassian Connect Express is a Node.js package for building Atlassian Connect apps. Authentication between Atlassian products and the Atlassian Connect Express app occurs with a server-to-server JWT or a context JWT. Atlassian Connect Express versions from 3.0.2 before 6.6.0 erroneously accept context JWTs in lifecycle endpoints (such as installation) where only server-to-server JWTs should be accepted, permitting an attacker to send authenticated re-installation events to an app.","status":"published","published":"2021-04-16T03:00:19Z","modified":"2025-02-12T20:46:54Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-03T00:03:55.950052Z"}],"ghsa":[{"id":"GHSA-4v96-m8xv-x83v","title":"Broken Authentication in Atlassian Connect Express","description":"Broken Authentication in Atlassian Connect Express (ACE) from version 3.0.2 before version 6.6.0: Atlassian Connect Express is a Node.js package for building Atlassian Connect apps. Authentication between Atlassian products and the Atlassian Connect Express app occurs with a server-to-server JWT or a context JWT. Atlassian Connect Express versions between 3.0.2 - 6.5.0 erroneously accept context JWTs in lifecycle endpoints (such as installation) where only server-to-server JWTs should be accepted, permitting an attacker to send authenticated re-installation events to an app.","status":"published","published":"2022-05-24T22:28:12Z","modified":"2025-02-12T21:53:05Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N","level":"high"}],"cwes":["CWE-287","CWE-863"],"updated_at":"2026-11-02T14:38:30.754382Z"}],"nvd":[{"id":"CVE-2021-26073","description":"Broken Authentication in Atlassian Connect Express (ACE) from version 3.0.2 before version 6.6.0: Atlassian Connect Express is a Node.js package for building Atlassian Connect apps. Authentication between Atlassian products and the Atlassian Connect Express app occurs with a server-to-server JWT or a context JWT. Atlassian Connect Express versions from 3.0.2 before 6.6.0 erroneously accept context JWTs in lifecycle endpoints (such as installation) where only server-to-server JWTs should be accepted, permitting an attacker to send authenticated re-installation events to an app.","status":"published","published":"2021-04-16T03:15:12.033Z","modified":"2026-06-17T03:42:48.113Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N","level":"high","assessor":"primary"},{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N","level":"high","assessor":"secondary"},{"version":"2.0","score":4,"vector":"AV:N/AC:L/Au:S/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:06:52.03307Z"}],"osv":[{"id":"GHSA-4v96-m8xv-x83v","title":"Broken Authentication in Atlassian Connect Express","description":"Broken Authentication in Atlassian Connect Express (ACE) from version 3.0.2 before version 6.6.0: Atlassian Connect Express is a Node.js package for building Atlassian Connect apps. Authentication between Atlassian products and the Atlassian Connect Express app occurs with a server-to-server JWT or a context JWT. Atlassian Connect Express versions between 3.0.2 - 6.5.0 erroneously accept context JWTs in lifecycle endpoints (such as installation) where only server-to-server JWTs should be accepted, permitting an attacker to send authenticated re-installation events to an app.","status":"published","published":"2022-05-24T22:28:12Z","modified":"2025-02-12T22:27:03.009299Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N","level":"high"}],"cwes":["CWE-287","CWE-863"],"updated_at":"2026-11-02T15:46:37.528068Z"}]}}