PatchSiren cyber security CVE debrief
CVE-2021-26085 Atlassian CVE debrief
CVE-2021-26085 is a pre-authorization arbitrary file read issue in Atlassian Confluence Server. CISA lists it in the Known Exploited Vulnerabilities catalog, with known ransomware campaign use marked as known. For defenders, the key signal is that affected Confluence Server instances should be patched promptly and validated for exposure.
- Vendor
- Atlassian
- Product
- Confluence Server
- CVSS
- Unknown
- CISA KEV
- Listed
- Original CVE published
- 2022-03-28
- Original CVE updated
- 2022-03-28
- Advisory published
- 2022-03-28
- Advisory updated
- 2022-03-28
Who should care
Organizations running Atlassian Confluence Server, especially internet-facing deployments, and teams responsible for patching, vulnerability management, and incident response.
Technical summary
The vulnerability is described as a pre-authorization arbitrary file read in Atlassian Confluence Server, meaning an attacker may be able to access files without first completing authorization. The supplied corpus does not include a CVSS score or deeper technical details, so remediation guidance should follow the vendor and CISA references.
Defensive priority
High. CISA added this CVE to KEV on 2022-03-28 and set a due date of 2022-04-18, indicating urgent remediation priority for affected environments.
Recommended defensive actions
- Apply Atlassian updates per vendor instructions.
- Identify all Confluence Server instances, including internet-facing and shadow deployments.
- Confirm whether any instance is affected and prioritize patching before or by the CISA due date if still unremediated.
- Review access logs and file-access related activity on affected systems for signs of misuse.
- If the product is exposed externally, increase monitoring and restrict access until remediation is complete.
Evidence notes
The supplied corpus identifies the CVE as an Atlassian Confluence Server pre-authorization arbitrary file read and confirms CISA KEV listing, dateAdded 2022-03-28, dueDate 2022-04-18, and known ransomware campaign use marked "Known". No CVSS score was provided in the corpus.
Official resources
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CVE-2021-26085 CVE record
CVE.org
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CVE-2021-26085 NVD detail
NVD
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CISA Known Exploited Vulnerabilities catalog
CISA - Apply updates per vendor instructions.
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Source item URL
cisa_kev
CVE published and added to CISA KEV on 2022-03-28; CISA due date was 2022-04-18.