---
cve: "CVE-2021-26073"
severity: "HIGH"
cvss: 7.7
epss: "92%"
vendor: "Atlassian"
kev: false
exploited: false
published: "2021-04-16 03:00:19"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-08T21:35:17+02:00"
---

# CVE-2021-26073

> 7.7 HIGH

## Beschreibung

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-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Keine | good |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Keine | good |

## Referenzen

- <https://confluence.atlassian.com/pages/viewpage.action?pageId=1051986099>
- <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://security.netapp.com/advisory/ntap-20210604-0004/>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-26073) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_