CISA KEV · Known exploitedCritical

CVE-2021-26084

Atlassian Confluence Server and Data Center

In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that would allow an unauthenticated attacker to execute arbitrary code on a Confluence Server or Data Center instance. The affected versions are before version 6.13.23, from version 6.14.0 before 7.4.11, from version 7.5.0 before 7.11.6, and from version 7.12.0 before 7.12.5.

CVSS: 9.8
EPSS: 100.0%
CISA KEV: Listed
Published: 2021.08.30

PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV

Exploit probability100.0%

Technical severityCVSS 9.8

Vulnerability overview

Affected product and versions

Product: Atlassian Confluence Server and Data Center
Affected versions: unspecified, 6.14.0, 7.5.0, 7.12.0, < 6.13.23, >= 6.14.0 < 7.4.11, >= 7.5.0 < 7.11.6, >= 7.12.0 < 7.12.5
Fixed versions: 6.13.23, 7.4.11, 7.11.6, 7.12.5

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

CISA required action

Apply updates per vendor instructions.

Due date: 2021.11.17

1
Identify
Confirm that Atlassian Confluence Server and Data Center and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-917
KEV added: 2021.11.03
Ransomware use: 확인됨