---
cve: "CVE-2021-26077"
severity: "CRITICAL"
cvss: 9.1
epss: "95%"
vendor: "Atlassian"
kev: false
exploited: false
published: "2021-05-10 00:15:07"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-11T08:27:32+02:00"
---

# CVE-2021-26077

> 9.1 CRITICAL

## Beschreibung

Broken Authentication in Atlassian Connect Spring Boot (ACSB) in version 1.1.0 before 2.1.3 and from version 2.1.4 before 2.1.5: Atlassian Connect Spring Boot is a Java Spring Boot package for building Atlassian Connect apps. Authentication between Atlassian products and the Atlassian Connect Spring Boot app occurs with a server-to-server JWT or a context JWT. Atlassian Connect Spring Boot versions 1.1.0 before 2.1.3 and versions 2.1.4 before 2.1.5 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:H/I:L/A:L
```

| 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 | Hoch | bad |
| I Integrität | Gering | warn |
| A Verfügbarkeit | Gering | warn |

## Referenzen

- <https://community.developer.atlassian.com/t/action-required-atlassian-connect-vulnerability-allows-bypass-of-app-qsh-verification-via-context-jwts/47072>
- <https://confluence.atlassian.com/pages/viewpage.action?pageId=1063555147>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-26077) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_