# CVE-2026-78691: Unescaped backslash allows LIKE wildcard injection in AshSql string search

> Attackers can inject SQL LIKE wildcards in AshSql string searches to bypass filters, probe data, or cause denial of service.

- **Severity:** Low 2.1 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Aug 2026
- **Updated:** 31 Aug 2026
- **Also known as:** EEF-CVE-2026-78691, GHSA-5jgp-7mhc-6qqh

## What is CVE-2026-78691?

CVE-2026-78691 is a low-severity SQL injection vulnerability in ash-project ash_sql, published on 30 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### 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.

Weakness: CWE-943 (Improper Neutralization of Special Elements in Data Query Logic)

## Which versions are affected by CVE-2026-78691?

1 open source package ship an affected version, including ash_sql.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ash_sql` | Hex | From 0.1.1-rc.10 | 0.7.1 |

## How do I fix CVE-2026-78691?

Upgrade ash_sql to 0.7.1 or later.

## Is CVE-2026-78691 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-78691 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-78691 and fix it if it is affected.

What it is: CVE-2026-78691 is a low-severity SQL injection vulnerability in ash-project ash_sql, published on 30 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-78691 exists.

Affected packages and fixed versions:
- ash_sql (Hex): affected from 0.1.1-rc.10; fixed in 0.7.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-78691/ (Markdown: https://insights.sbomify.com/CVE-2026-78691/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-78691
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-78691
- OSV: https://osv.dev/vulnerability/CVE-2026-78691

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-78691/
Summaries are generated and may contain mistakes; the official description above is the record.