CVE-2026-55442: Goobi viewer: cleanUpQuery double-brace bypass allows arbitrary Solr local-param injection

Vulnerability summary

CVE-2026-55442 is a medium (CVSS 5.3) Improper Input Validation vulnerability in intranda goobi-viewer-core.

Timeline

1. 23-10-2026
   PublishedVulnerability first disclosed.

Description

The Goobi viewer is a web application that allows digitised material to be displayed in a web browser. From version 23.03 to before version 26.05, SolrTools.cleanUpQuery() strips Solr local-parameter syntax ({!...}) from user-supplied query strings before they reach Solr. Its regex can be bypassed by wrapping the local parameter in a second pair of curly braces ({{!...}}): the outer braces are stripped, the inner {!...} survives intact, and a valid Solr local parameter is forwarded. The flaw is in the shared sanitizer, so it affects any endpoint that routes user input through cleanUpQuery. The double-brace bypass applies from v23.10 (the greedy \{(.+)\} regex); a related bare-!join rewrap path is present. This issue has been patched in version 26.05.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
• CWE-116Improper Encoding or Escaping of OutputThe product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.