CVE-2021-26073

HIGH
7.7
CVSS Score
Published: April 16, 2021 at 03:00 AM UTC
Updated: June 17, 2026 at 03:42 AM UTC
1 product affected across 1 vendorConnect Express

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Severity
HIGH7.7
Exploit prediction
EPSS 0.9%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≥ 3.0.2v < 6.6.03.0.2 ≤ v < 6.6.03.0.2
Affected range stops below 6.6.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.7HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-287

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