EEF-CVE-2026-78691

## Summary

Improper Neutralization of Special Elements in Data Query Logic vulnerability in ash-project ash\_sql allows a user who supplies a search term to contains/2, string\_starts\_with/2, or string\_ends\_with/2 to inject live SQL LIKE wildcards, turning a literal substring search into an attacker-controlled pattern match.

The escape helpers in AshSql.Expr prefix % and \_ with a backslash but never escape a backslash already present in the input. Because backslash is the default LIKE escape character, the escaping defeats itself: the input \\% becomes the pattern fragment \\\\%, where \\\\ is a literal backslash and the attacker's % remains a live wildcard. The search value stays parameterized, so this is confined to the LIKE pattern grammar rather than full SQL. An attacker can widen matches to probe values, slip past a negated contains(...) guard, or crash the query with a trailing lone backslash.

This issue affects ash\_sql: from 0.1.1-rc.10 before 0.7.1.

## Configuration

An application must pass untrusted input as the search term of contains/2, string\_starts\_with/2, or string\_ends\_with/2 (for example a user-controlled substring search).