CVE-2021-26085

MEDIUM

5.3

CVSS Score

Published: August 3, 2021 at 12:00 AM UTC

Updated: June 17, 2026 at 03:42 AM UTC

2 products affected across 1 vendorConfluence ServerConfluence Data Center

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Severity

MEDIUM5.3

Exploitation

CISA KEV

Exploit prediction

EPSS 100%

SSVC

Active

Actively Exploited

CISA Known Exploited Vulnerabilities (KEV) Catalog

EPSS Score99.9%

EPSS (Exploit Prediction Scoring System) estimates a 99.9% chance this CVE is exploited in the wild within the next 30 days — higher than 100% of all CVEs. It complements CVSS: a high EPSS on a mid-severity CVE can still be urgent.

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.

Ransomware Use

Known

Added to KEV

Mar 28, 2022

Remediation Due

Apr 18, 2022

1655 days overdue

Notes

https://nvd.nist.gov/vuln/detail/CVE-2021-26085

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Confluence Data Center · Atlassianatlassian-app

95%

v ≥ 7.5.0v < 7.12.3v < 7.4.107.5.0 ≤ v < 7.12.37.5.0

Affected range stops below 7.12.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.4.10, so it looks safe — our inference, not a vendor statement

Confluence Server · Atlassianatlassian-app

95%

v ≥ 7.5.0v < 7.12.3v < 7.4.107.5.0 ≤ v < 7.12.37.5.0

Affected range stops below 7.12.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.4.10, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://jira.atlassian.com/browse/CONFSERVER-67893

References (3)

x_refsource_MISCExploitThird Party AdvisoryVDB Entry

Source: [email protected]

http://packetstormsecurity.com/files/164401/Atlassian-Confluence-Server-7.5.1-Arbitrary-File-Read.html

x_refsource_MISCIssue TrackingVendor Advisory

Source: [email protected]

https://jira.atlassian.com/browse/CONFSERVER-67893

US Government Resource

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26085

SSVC — Action Prioritization

SSVCActiveAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMCISA-ADP

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: LOW
Integrity: NONE
Availability: NONE

Vector?

Quick Info

StatusANALYZED

CWE

CWE-425

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