CVE-2026-117537

REDAXO before 5.21.0 contains a reflected cross-site scripting vulnerability in the backend packages API, where the function parameter is concatenated into an error message rendered without HTML escaping. Attackers can lure an authenticated backend user to a crafted link containing a valid CSRF token, executing JavaScript that performs same-origin actions or reads DOM data.

REDAXO before 5.21.3 contains a cross-site request forgery vulnerability in the backend user administration page (users/users) because the CSRF token check only runs when the save parameter is set, while the update path triggered by FUNC_UPDATE does not require it. Attackers can lure a logged-in backend user with the users[] permission to a crafted GET link to grant administrator rights, deactivate accounts, or lock out the sole administrator.

REDAXO before 5.21.3 contains a reflected cross-site scripting vulnerability in the backend media pool detail page, where the opener_link parameter is rendered without HTML escaping. Unauthenticated attackers can lure logged-in backend users with media permissions into clicking a crafted link. The injected script can then read the CSRF token and perform actions with the victim's permissions, including code execution via template or module edits when the victim is an administrator.

REDAXO before 5.21.3 contains a cross-site request forgery vulnerability in the structure/history plugin that allows attackers to delete history or roll back content via unvalidated GET requests. Attackers can lure logged-in backend users to a page triggering func=clearall or rex_history_function=snap, permanently deleting all article snapshots or reverting articles to earlier states.

REDAXO from 5.18.0 before 5.21.4 contains a stored cross-site scripting vulnerability because rex_media_service moves uploaded SVG files into the public media folder before sanitizing them. Authenticated users with mediapool upload rights can race the sanitizer or exhaust memory limits to leave script-laden SVGs publicly served, executing scripts in victims' backend sessions.

REDAXO before 5.21.4 contains a stored cross-site scripting vulnerability that allows content editors to inject HTML by storing unescaped values rendered by media, medialist, link and linklist widgets. Attackers can submit crafted REX_INPUT_MEDIA or REX_INPUT_LINK values that break out of the value attribute and execute script in administrators' backend sessions.

REDAXO before 5.21.4 contains a broken access control vulnerability that allows authenticated editors to modify slices in unauthorized categories by pairing a permitted article with a foreign slice id. Attackers can abuse content/edit delete and edit functions or the content_slice_status and content_move_slice APIs to delete, toggle, move, or overwrite other editors' slices.

REDAXO before 5.21.4 contains a missing authorization vulnerability in media pool bulk move that checks only target category permission, ignoring the source category. Authenticated backend users with permission for one media category can move files from restricted categories into it and silently replace their contents site-wide.

REDAXO core before 5.21.4 contains a missing authorization vulnerability in the structure/version and structure/history frontend preview modes, which do not check category or clang permissions for the previewed article. Any backend user, or one holding history[article_rollback], can set rex_version or rex_history_date with arbitrary article_id values to read unpublished working versions and historic or deleted content.

REDAXO before 5.21.5 contains a missing authorization vulnerability in the backup addon export that accepts any database table. Non-admin users with the backup[export] permission can export rex_user, rex_user_session, and other applications' tables, obtaining plaintext session IDs and stay-logged-in keys to take over admin accounts, or password hashes for offline cracking.