Atlassian Confluence Data Center and Server Broken Access Control Vulnerability
Atlassian has been made aware of an issue reported by a handful of customers where external attackers may have exploited a previously unknown vulnerability in publicly accessible Confluence Data Center and Server instances to create…
Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.
Exploitation probability EPSS · FIRST
Exploitation signals 5 / 5
- KEV catalog (CISA)05 Oct 2023
- Exploited in EUVD (ENISA)05 Oct 2023
- Used by ransomwareyes
- EPSS above 10 %99.2%
- No account, over the networkyes
What to do
Fix
Apply the vendor’s fix as soon as it is available.
CISA guidance: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. Check all affected Confluence instances for evidence of compromise per vendor instructions and report any positive findings to CISA.
Meanwhile
Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.
Manufacturers (CRA)
Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained
Description ENISA EUVD
Atlassian has been made aware of an issue reported by a handful of customers where external attackers may have exploited a previously unknown vulnerability in publicly accessible Confluence Data Center and Server instances to create unauthorized Confluence administrator accounts and access Confluence instances. Atlassian Cloud sites are not affected by this vulnerability. If your Confluence site is accessed via an atlassian.net domain, it is hosted by Atlassian and is not vulnerable to this issue.
Affected products
- 8.2.3
- 8.3.0
- 8.3.2
- 8.3.1
- 8.4.2
- 8.0.3
- 8.2.2
- 8.0.0
- 8.5.0
- 8.5.1
- 8.0.2
- 8.4.1
Open source packages OSV
Affected libraries according to OSV, with fixed versions.
Timeline
-
Published
-
Exploitation reported (ENISA)
-
Added to the KEV catalog
-
CISA remediation due date
-
EPSS peak: 99.2%
References
Other exploited vulnerabilities from the same vendor
- CVE-2026-21589Atlassian Multiple Products Files or Directories Accessible to External Parties Vulnerability9.1 · Rising fast
- CVE-2021-26086Atlassian Jira Server and Data Center Path Traversal Vulnerability7.5 · Background exploitation
- CVE-2023-22527Atlassian Confluence Data Center and Server Template Injection Vulnerability10.0 · Background exploitation
- CVE-2023-22518Atlassian Confluence Data Center and Server Improper Authorization Vulnerability10.0 · Background exploitation
- CVE-2022-36804Atlassian Bitbucket Server and Data Center Command Injection Vulnerability8.3 · Background exploitation
- CVE-2022-26138Atlassian Questions For Confluence App Hard-coded Credentials Vulnerability9.3 · Background exploitation