CVE-2026-86338
Published:September 16, 2026
Updated:September 22, 2026
Ash field_policies are documented to protect against filter-based information disclosure: when a field the actor may not see is referenced in a filter, it is replaced with an expression that evaluates to nil, so a filter cannot be used as a yes/no oracle to read a value the actor cannot see.
This nilling was applied to attributes but not to calculations or aggregates. A user-supplied filter reference to a calculation or aggregate carries an Ash.Query.Calculation / Ash.Query.Aggregate struct, which the authorizer's reference replacement did not match (it only matched the Ash.Resource.* structs), so the filter ran against the real value.
As a result, an actor whose field policies forbid a calculation or aggregate can still filter by it (for example filter(secret_calc == "x") or filter(comment_count == n)) and learn the value from whether rows match — an oracle that recovers field-policy-protected values one probe at a time. Filtering is commonly exposed to lower-privileged actors (for example via AshGraphql or AshJsonApi filter arguments), which is exactly the surface field policies are meant to protect.
The fix routes filter references to calculations and aggregates through the same field-policy nilling as attributes.
This issue affects ash: from 2.11.0-rc.0 before 3.33.4.
Affected Packages
https://github.com/ash-project/ash.git (GITHUB):
Affected version(s) >=3.0.3 <3.33.4Fix Suggestion:
Update to version 3.33.4ash (HEX):
Affected version(s) >=2.11.0-rc.0 <3.33.4Fix Suggestion:
Update to version 3.33.4Related Resources (6)
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Contact UsCVSS v4
Base Score:
6
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Insufficient Granularity of Access Control
EPSS
Base Score:
0.32