SA-CONTRIB-2026-126: Critical severity drupal/islandora vulnerability
This islandoraadvancedsearch sub module enables AJAX updates for advanced search, facet, and search result blocks. The module doesn't sufficiently check block access when arbitrary block ID's are submitted to its publicly accessible AJAX endpoint. This may allow an unauthenticated attacker to retrieve restricted block content. This vulnerability is mitigated by the fact that an attacker must know or guess a restricted block’s machine ID, and the block must contain sensitive content protected by block access or visibility restrictions. Additionally, the submodule is not known to be used by any modern Islandora configurations.
Credit
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Restrict access to the publicly accessible AJAX endpoint provided by the islandora_advanced_search submodule (the AJAX updates for advanced search, facets, and search result blocks) so unauthenticated users cannot query arbitrary block IDs.
Event History
Frequently Asked Questions
Who is realistically exposed to this issue?
Sites using the islandora_advanced_search submodule are exposed if they have restricted blocks containing sensitive content. The submodule is not known to be used by modern Islandora configurations.
What does an attacker need to exploit it?
An unauthenticated attacker must know or successfully guess the machine ID of a restricted block. The issue is only meaningful when that block's content is protected by block access or visibility restrictions and contains sensitive information.
Are default or publicly visible blocks affected?
The disclosed impact concerns restricted blocks submitted by arbitrary block ID to the publicly accessible AJAX endpoint. The data does not indicate exposure of content that is already publicly visible.