CVE-2021-26085 Atlassian Confluence Server Pre-Authorization Arbitrary File Read

Exploited in the wild Medium 5.3 Published 3 Aug 2021 Updated 21 Oct 2025

Remote attackers can view restricted resources via an arbitrary file read vulnerability in the /s/ endpoint of Atlassian Confluence Server.

Exploited in the wild: Since 28 Mar 2022
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-26085?

CVE-2021-26085 is a medium-severity path traversal vulnerability in Atlassian Confluence Data Center, published on 3 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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. The affected versions are before version 7.4.10, and from version 7.5.0 before 7.12.3.

Weakness: CWE-425

Which versions are affected by CVE-2021-26085?

It affects 2 products.

Products include Atlassian Confluence Data Center, Atlassian Confluence Server.

How do I fix CVE-2021-26085?

No fix has been published for CVE-2021-26085 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 18 Apr 2022.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2021-26085 being exploited?

Yes. Attackers have exploited CVE-2021-26085 in the wild since at least 28 Mar 2022, including in ransomware campaigns.

Public exploit code: 1 Exploit-DB entry, 1 Nuclei template and 1 proofs of concept on GitHub.

Sources

Also known as GHSA-8mjc-qhq2-3xm8.