CVE-2021-26085

Exp

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.

Published: 2021-08-02 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-26085 is rated Critical Active Threat (86.2/100): CVSS Medium severity, with high exploitation likelihood (EPSS 99.94%, 100th percentile). CISA KEV confirms active exploitation (added 2022-03-28) affecting Atlassian / Confluence Server. a weakness (CWE-425) Unauthenticated remote administrative access may be possible. EPSS rose +5.96% over the last day, indicating growing attacker interest. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2021-26085

Name: Atlassian Confluence Server Pre-Authorization Arbitrary File Read Vulnerability · CISA KEV detail

Exploit added: 2022-03-28

Action due: 2022-04-18

Required action: Apply updates per vendor instructions.

Public exploit references (Exploit-DB) for CVE-2021-26085

EDB-ID Source Kind Published Link
50377 exploit_db edb 2021-10-05 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-26085

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 93.98% 99.94% +5.96%
2 2026-03-04 93.92% 93.98% +0.06%
3 2026-03-01 — 93.92% —

Full EPSS history (36 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-26085

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 134c704f-9b21-4f2e-91b3-4a467353bcc0
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-26085

Affected software / configurations for CVE-2021-26085

Vendor Product Version Raw CPE
atlassian confluence_data_center < 7.4.10 cpe:2.3:a:atlassian:confluence_data_center:*:*:*:*:*:*:*:*
atlassian confluence_data_center >= 7.5.0, < 7.12.3 cpe:2.3:a:atlassian:confluence_data_center:*:*:*:*:*:*:*:*
atlassian confluence_server < 7.4.10 cpe:2.3:a:atlassian:confluence_server:*:*:*:*:*:*:*:*
atlassian confluence_server >= 7.5.0, < 7.12.3 cpe:2.3:a:atlassian:confluence_server:*:*:*:*:*:*:*:*

References for CVE-2021-26085

cvelogic Threat Intelligence