CVE-2021-26085
Atlassian Confluence Server Pre-Authorization Arbitrary File Read Vulnerability
- Medium 5.3
- Exploited: added to CISA KEV 28 Mar 2022
- Used in ransomware campaigns
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.
Key facts
- Published
- 3 Aug 2021
- Last changed
- 21 Oct 2025
- Assigned by
- atlassian
- KEV added
- 28 Mar 2022
- KEV fix due
- 18 Apr 2022
- Used in ransomware
- Yes, according to CISA
- EPSS
- 99.937% likely to be exploited in the next 30 days, higher than 99.971% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: yes; Technical impact: partial
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 5.3CVSS 3.1, Mediumfrom CISA (ADP container)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
What to do
- Apply updates per vendor instructions.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Atlassian | Confluence Server |
|
| Atlassian | Confluence Data Center |
|
Timeline
- 3 Aug 2021 Published
- 28 Mar 2022 CVE-2021-26085 added to CISA KEV
- 28 Mar 2022 Added to the CISA KEV catalogue