CVE-2021-26084

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

In the wild

CISA lists this as exploited in real attacks. Treat as urgent.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-01-25 00:00 UTC ReservedThe CVE id was reserved by its CNA
2. 2021-08-30 07:15 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2021-11-03 Exploited in the wildAdded to CISA's Known Exploited Vulnerabilities list
4. 2021-11-17 Remediation deadlineCISA's due date for federal agencies to fix it
5. 2026-06-17 03:42 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: yes, CISA lists it. This puts it above everything that is not.
• Exploit odds: 100.0% in the next 30 days (EPSS).
• Severity: 9.8 CRITICAL (CVSS).
• Fix: a patch or advisory is linked.
• It meets the bar for Drop everything: critical, and exploited or very likely to be.

Details

Published

2021-08-30 07:15 UTC

Last modified

2026-06-17 03:42 UTC

Added to CISA KEV

2021-11-03

Exploit probability

100.0% · EPSS, next 30 days

Weakness

CWE-917

Record status

Analyzed

Affected

• Atlassian Confluence Data Center < 6.13.23
• Atlassian Confluence Data Center < 7.4.11
• Atlassian Confluence Data Center < 7.11.6
• Atlassian Confluence Data Center < 7.12.5
• Atlassian Confluence Server < 6.13.23
• Atlassian Confluence Server < 7.4.11
• Atlassian Confluence Server < 7.11.6
• Atlassian Confluence Server < 7.12.5

Attack profile CVSS 3.1 · 9.8

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-26084.md and follow it. Check whether this project is affected by CVE-2021-26084. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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