Vulnerability · Published Aug 30, 2026 · Assigned by EEF
CVE-2026-78691Unescaped backslash allows LIKE wildcard injection in AshSql string search
Low 2.1
In plain English
A low-severity security flaw in ash_sql from ash-project. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ash-project | ash_sql | 0.1.1-rc.10 – before 0.7.1 |
| ash-project | ash_sql | cfc7da474c5be2190fd62664a83a689377a8d512 – before d95c55c64b1b42cc2fd30211a4913f3145156cd4 |
Weakness: CWE-943 · 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
References
- https://github.com/ash-project/ash_sql/security/advisories/GHSA-5jgp-7mhc-6qqh vendor-advisory, related
- https://cna.erlef.org/cves/CVE-2026-78691.html related
- https://osv.dev/vulnerability/EEF-CVE-2026-78691 related
- https://github.com/ash-project/ash_sql/commit/d95c55c64b1b42cc2fd30211a4913f3145156cd4 patch