CVE-2026-78691 PUBLISHED

Unescaped backslash allows LIKE wildcard injection in AshSql string search

Assigner: EEF
Reserved: 30.08.2026 Published: 30.08.2026 Updated: 30.08.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS Score: 2.1

Product Status

Vendor ash-project
Product ash_sql
Versions Default: unaffected
  • affected from 0.1.1-rc.10 to 0.7.1 (excl.)
Vendor ash-project
Product ash_sql
Versions Default: unaffected
  • affected from cfc7da474c5be2190fd62664a83a689377a8d512 to d95c55c64b1b42cc2fd30211a4913f3145156cd4 (excl.)

Affected Configurations

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).

Credits

  • Peter Ullrich finder
  • Peter Ullrich reporter
  • Zach Daniel / Ash Project remediation developer
  • Jonatan Männchen / EEF coordinator

References

Problem Types

  • CWE-943 Improper Neutralization of Special Elements in Data Query Logic CWE

Impacts

  • CAPEC-116 Excavation