# CVE-2026-77454: exists/2 predicate silently dropped on limited relationships with a parent() filter in AshSql

> Attackers can bypass authorization policies in AshSql by exploiting a bug that silently drops exists predicates on limited relationships with parent filters.

- **Severity:** Medium 5.9 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/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-2026-77454, GHSA-8v9m-8pxv-738c

## What is CVE-2026-77454?

CVE-2026-77454 is a medium-severity missing authorization 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

Incorrect Authorization vulnerability in ash-project ash_sql allows a caller to bypass a scoping or authorization filter expressed as exists/2 over a relationship that declares both a limit (or from_many?) and a parent(...)-referencing filter or sort.

AshSql.Join.related_query/3 skips the caller-supplied exists predicate for such relationships and delegates it to limit_from_many/5. When the relationship's own filter or sort references parent(...), limit_from_many/5 takes a branch that drops both the limit and the predicate, emitting a bare correlated EXISTS with no predicate. The check then matches any record that has any related row. Most severely, when the expression backs a policy (for example authorize_if expr(exists(memberships, user_id == ^actor(:id)))), the actor-scoping condition disappears and the policy passes for any actor with any related row.

This issue affects ash_sql: from 0.4.1 before 0.7.1.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-77454?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ash_sql` | Hex | From 0.4.1 | 0.7.1 |

## How do I fix CVE-2026-77454?

Upgrade ash_sql to 0.7.1 or later.

## Is CVE-2026-77454 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77454 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-77454 and fix it if it is affected.

What it is: CVE-2026-77454 is a medium-severity missing authorization 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-2026-77454 exists.

Affected packages and fixed versions:
- ash_sql (Hex): affected from 0.4.1; 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-2026-77454/ (Markdown: https://insights.sbomify.com/CVE-2026-77454/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-77454
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77454
- OSV: https://osv.dev/vulnerability/CVE-2026-77454

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-77454/
Summaries are generated and may contain mistakes; the official description above is the record.