CVE-2026-82749: Ash relationship parent(...) filter degrades to an IS NULL match when the parent field is unresolved, leaking scoped records

Severity: medium (CVSS 5.9 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-01 · updated 2026-09-01
Weakness: CWE-863

Description

Incorrect Authorization vulnerability in ash-project ash widens a relationship's parent(...) scoping filter to match unintended records when the referenced parent field cannot be resolved. Loading a relationship whose filter references parent(...) resolves that expression against the parent record. resolve_parent_in_filter/3 (lib/ash/actions/read/relationships.ex) resolved an unresolvable parent reference (for example when the referenced field was not selected on the source query) to nil rather than failing. A scoping predicate such as org_id == parent(org_id) then becomes an IS NULL match, and a guard like is_nil(parent(org_id)) or org_id == parent(org_id) activates its unrestricted branch, so the relationship returns records the scope was meant to exclude. The fix fails the read with an error when a parent(...) reference cannot be resolved, instead of defaulting to nil. This issue affects ash: from 3.13.2 before 3.32.2.

Affected products

ash-project ash: from 3.13.2 before 3.32.2 — fixed in 3.32.2

How to fix

Upgrade to a fixed version: ash-project ash 3.32.2. Check the vendor advisory for mitigations.

References

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