CISA KEV entry
CVE-2021-26085Atlassian Confluence Server Pre-Authorization Arbitrary File Read Vulnerability
Atlassian Confluence Server. Added to the CISA Known Exploited Vulnerabilities catalogue on 28 March 2022.
Data status: a source is stale
Last synced CISA catalogue version 2026.11.04 (released 4 November 2026) 1,768 entries Updated manually
- Date added
- 2022-03-28
- Federal due date
- 2022-04-18 21 days after it was added; passed at the sync of 2026-11-05
- Known ransomware use
- Known
- Forensic triage (BOD 26-04)
- No
- CVSS
- 5.3 Medium CVSS 3.1, scored by nvd@nist.gov
- EPSS
- 99.93% percentile 99.9, scored 2026-11-04
- CISA SSVC
- Exploitation active, automatable yes, technical impact partial
- NVD status
- Analyzed published 2021-08-03, 237 days before the KEV listing
BOD 26-04 remediation window
With CISA's SSVC answers for this CVE (automatable: yes, technical impact: partial), BOD 26-04 Table 1 gives 3 days on a publicly exposed asset (row 2) and 14 days on an asset that is not publicly exposed (row 10) S06. The catalogue due date, 21 days after the date added, was set before BOD 26-04 took effect on 10 June 2026 S06. The directive binds US federal civilian executive branch agencies only.
What CISA says
Short 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.
Required action
Apply updates per vendor instructions.
Notes
https://nvd.nist.gov/vuln/detail/CVE-2021-26085
CWE in the catalogue
CWE-425
Official links
- CISA KEV catalogue entry cisa.gov
- NVD record nvd.nist.gov
Vendor advisory and patch links
References NVD tags Vendor Advisory or Patch, exactly as NVD lists them.
- https://jira.atlassian.com/browse/CONFSERVER-67893 Issue Tracking, Vendor Advisory
Links in CISA's notes
NVD details
- CWE (NVD)
- CWE-425 by nvd@nist.gov
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N- CVSS versions in NVD
- V2, V31
- Last modified in NVD
- 2026-06-17T03:42:49.933
Where each value comes from
| Field | Source | Fetched, UTC | State |
|---|---|---|---|
| Catalogue fields | CISA KEV JSON, version 2026.11.04 | 2026-11-05 11:38 | current |
| NVD published, status, CVSS, CWE, vendor links | NVD CVE API 2.0; CVSS: NVD (nvd@nist.gov) | 2026-11-03 12:37 | current at 2026-11-05 11:38 |
| EPSS | FIRST EPSS API, scores of 2026-11-04 | 2026-11-05 11:38 | current |
| CISA SSVC | CISA ADP (via NVD), record of 2025-02-07 | 2026-11-03 12:37 | current |
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