{"cve":"CVE-2021-26073","nvd":{"published":"2021-04-16T03:15:12.033","modified":"2026-06-17T03:42:48.113","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N","score":7.7},"cwes":["CWE-287"],"references":["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","https://confluence.atlassian.com/pages/viewpage.action?pageId=1051986099","https://security.netapp.com/advisory/ntap-20210604-0004/","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","https://confluence.atlassian.com/pages/viewpage.action?pageId=1051986099"],"products":["atlassian:connect_express"],"source":"nvd","synced_at":"2026-10-19T21:17:01.373894544+00:00"},"epss":{"cve":"CVE-2021-26073","score":0.00915,"percentile":0.60143,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-4v96-m8xv-x83v","url":"https://osv.dev/vulnerability/GHSA-4v96-m8xv-x83v","summary":"Broken Authentication in Atlassian Connect Express","modified":"2025-02-12T22:27:03.009299Z","packages":[{"ecosystem":"npm","name":"atlassian-connect-express","purl":"pkg:npm/atlassian-connect-express","ranges":[">=3.0.2 <6.6.0"],"fixed":["6.6.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}