CVE-2026-42579

*This is a vulnerability in a non-Atlassian Confluence dependency. Atlassian's application of this dependency presents a lower, non-critical assessed risk.* This Critical severity Injection vulnerability was introduced in versions 7.0.1, 7.4.0, 7.13.0, 7.19.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0, and 10.2.0 of Confluence Data Center. This Injection vulnerability, with a CVSS Score of 9.1 and a CVSS Vector of CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H allows an unauthenticated attacker to modify the actions taken by a system call which has no impact to confidentiality, high impact to integrity, high impact to availability, and requires no user interaction. 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 9.2.21 * Confluence Data Center 10.2: Upgrade to a release greater than or equal to 10.2.13 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]). The National Vulnerability Database provides the following description for this vulnerability: Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the decoder, and user-influenced hostnames can exploit the encoder. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

EPSS 1.01% · 60.4th percentile