Is CVE-2021-26073 actively exploited?

No active exploitation of CVE-2021-26073 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-26073 be exploited remotely?

Yes. CVE-2021-26073 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-26073?

CVE-2021-26073 has a CVSS score of 7.7 (HIGH).

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HIGH

CVE-2021-26073

CWE-287Published: April 16, 2021· Updated: Jun 17, 2026

7.7

CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-26073 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 7.7.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

From a weakness classification perspective (CWE-287): Authentication bypass vulnerabilities allow attackers to access protected resources without valid credentials.