Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Attack requirements (AT:P) | Attack requirements present |
| Privileges required (PR:N) | No privileges required |
| User interaction (UI:N) | No user interaction |
| Confidentiality (VC:H) | High confidentiality impact |
| Integrity (VI:N) | No integrity impact |
| Availability (VA:N) | No availability impact |
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
About Atlassian Confluence Data Center
CVE-2026-21579 affects Atlassian Confluence Data Center, a product from Atlassian. Before acting, confirm where Atlassian Confluence Data Center runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: This High severity Information Disclosure vulnerability was introduced in versions 7.17.0, 7.19.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 10.0.2, 10.1.0, and 10.2.0 of Confluence Data Center. This Information Disclosure vulnerability, with a CVSS Score of 8.2, allows an unauthenticated attacker to view sensitive information via an Information Disclosure vulnerability. Atlassian recommends that Confluence Data Center customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions: Confluence Data Center 9.2: Upgrade to a release greater than or equal to 9.2.22 Confluence Data Center 10.2: Upgrade to a release greater than or equal to 10.2.14 See the release notes ([https://confluence.atlassian.com/doc/confluence-release-notes-327.html]). You can download the latest version of Confluence Data Center from the download center ([https://www.atlassian.com/software/confluence/download-archives]). This vulnerability was reported via our Atlassian (Internal) program.
The weakness class is Information Exposure. Sensitive information is shown to someone who should not see it.
Based on its CVSS vector, the flaw can be reached over the network, needs no login, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Atlassian Confluence Data Center |
| Affected versions | Confluence Data Center from 7.19.26 up to and including 7.19.30; Confluence Data Center from 8.5.14 up to and including 8.5.31; Confluence Data Center from 8.9.5 up to and including 8.9.8; Confluence Data Center from 9.0.1 up to and including 9.0.3; Confluence Data Center from 9.1.0 up to and including 9.1.1; Confluence Data Center from 9.2.0 up to and including 9.2.21; Confluence Data Center from 10.0.2 up to and including 10.0.3; Confluence Data Center from 10.1.0 up to and including 10.1.2; Confluence Data Center from 10.2.0 up to and including 10.2.13 |
| Published | Jul 21, 2026 |
| Last modified | Aug 11, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | security@atlassian.com |
How to detect it
- Inventory every instance of Atlassian Confluence Data Center and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Atlassian Confluence Data Center named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Atlassian Confluence Data Center to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-200: Information Exposure More CVEs with this weakness
Technical References
Frequently asked questions
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