CVE-2021-26084 — Atlassian Confluence Server and Data Center Object-Graph Navigation Language (OGNL) Injection Vulnerability

CVE-2021-26084 (Atlassian Confluence Server and Data Center) is in the CISA Known Exploited Vulnerabilities catalog since 2021-11-03. Used in ransomware. Atlassian Confluence Server and Data Server contain an Object-Graph Navigation Language (OGNL) injection… See the required fix, due date and…

Exploitation status

CVE-2021-26084 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 2021-11-03. Atlassian Confluence Server and Data Server contain an Object-Graph Navigation Language (OGNL) injection vulnerability that may allow an unauthenticated attacker to execute code.

Advisory facts

Vendor or project
Atlassian
Affected product
Confluence Server and Data Center
Added to CISA KEV
2021-11-03
US federal remediation due date
2021-11-17
Ransomware association
Known
EPSS score
—
Weakness (CWE)
CWE-917

Remediation: the required action

Apply updates per vendor instructions.

Wording published by CISA for this catalog entry. It is the baseline action, not a decision about your environment: whether this exposure matters for you depends on where the affected component runs, what it is exposed to and who owns it.

From advisory to a decision you can defend

A catalog entry tells you a vulnerability is being exploited somewhere. It does not tell you whether it matters in your estate, who owns the fix, or what evidence an auditor will ask for later. That is the work VulnTrek does: it takes findings from the tools you already run, decides which exposure actually matters, routes it to an owner, keeps remediation human-approved and retains the lineage as evidence.

Sourced from public upstream advisories (CISA KEV, ENISA EUVD, vendor PSIRTs) mirrored daily. Informational only — not a remediation decision, not legal advice, and the absence of a record is not evidence of safety.