CVE-2025-53836: 
Java vulnerability analysis and mitigation

CVE-2025-53836 affects XWiki Rendering, a generic rendering system that converts textual input between different syntaxes. The vulnerability was discovered in version 4.2-milestone-1 and affects versions prior to 13.10.11, 14.4.7, and 14.10. The issue was disclosed on July 14, 2025, and involves the default macro content parser failing to preserve restricted attributes during nested macro execution (GitHub Advisory).

The vulnerability stems from the default macro content parser's failure to preserve the restricted attribute of the transformation context when executing nested macros. This security flaw allows the execution of macros that are normally forbidden in restricted mode, particularly script macros. The vulnerability affects the cache and chart macros bundled with XWiki. The issue has been assigned a CVSS v3.1 base score of 9.9 (CRITICAL) with the vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H (GitHub Advisory).

The vulnerability enables privilege escalation from comment rights to programming rights, potentially leading to remote code execution (RCE). Attackers can exploit this by using nested macros within comments to execute arbitrary code, including script macros that should be restricted. This allows unauthorized users to compromise the application server and its data (GitHub Advisory, XWIKI-20375).

The vulnerability has been patched in XWiki versions 13.10.11, 14.4.7, and 14.10. As a temporary workaround, administrators can disable comments for untrusted users until upgrading to a patched version. However, users with edit rights will still be able to add comments via the object editor even if comments are disabled (GitHub Advisory).

The vulnerability was initially reported on Intigriti by security researcher René de Sain (@renniepak). The discovery led to the creation of a security advisory and subsequent patches to address the issue (GitHub Advisory).