Hazard

Is CVE-2021-26085 being exploited?

Ransomware crews are using this

CISA has linked this vulnerability to known ransomware campaigns. Treat any exposed instance as an active incident, not a patching ticket.

Atlassian Confluence Server Pre-Authorization Arbitrary File Read Vulnerability

Atlassian · Confluence Server

CVSS 5.3 EPSS 100% 1 public exploit ransomware Fix deadline passed 18 April 2022

What it is

Affected versions of Atlassian Confluence Server allow remote attackers to view restricted resources via a pre-authorization arbitrary file read vulnerability in the /s/ endpoint.

Why we say that

  • Linked by CISA to known ransomware campaigns
  • EPSS puts exploitation in the next 30 days at 100%
  • 1 public exploit published
  • CISA's federal remediation deadline (2022-04-18) has passed
  • Listed in the CISA Known Exploited Vulnerabilities catalogue

Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.

What to do

Apply updates per vendor instructions.

Public exploit code

Indexed from Exploit-DB. Presence of code raises urgency; absence does not mean safety.

What it costs when this goes wrong

This is where UK enforcement meets the vulnerability record. This vulnerability is used in ransomware campaigns; here is what ransomware has cost UK organisations at the regulator.

All UK cases caused by ransomware →