---
id: CVE-2026-93477
title: >-
  Improperly Controlled Modification of Dynamically-Determined Object Attributes
  vulnerability in ash-project ash allows a user to set the value of a private
  action argument on the bulk destroy and bulk update paths.


  Action arguments decl…
summary: >-
  Improperly Controlled Modification of Dynamically-Determined Object Attributes
  vulnerability in ash-project ash allows a user to set the value of a private
  action argument on the bulk destroy and bulk update paths.


  Action arguments decl…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-915
vendor: ash-project
product: ash
affected:
  - ash >= 2.17.15 < 3.33.11
  - >-
    ash-project/ash >= 8c17434803b2e91de522bdfbd0ca918e5d5898df <
    6b7ac53a0a2532291eb940d7beaf0fbb2da6fc4f
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T07:16:56.163'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93477'
references:
  - url: 'https://cna.erlef.org/cves/CVE-2026-93477.html'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/ash-project/ash/commit/6b7ac53a0a2532291eb940d7beaf0fbb2da6fc4f
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/ash-project/ash/commit/8c17434803b2e91de522bdfbd0ca918e5d5898df
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://github.com/ash-project/ash/security/advisories/GHSA-c2p4-p7q6-hr2j'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://osv.dev/vulnerability/EEF-CVE-2026-93477'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-09-25T08:01:56.737Z'
---

## Overview

Improperly Controlled Modification of Dynamically-Determined Object Attributes vulnerability in ash-project ash allows a user to set the value of a private action argument on the bulk destroy and bulk update paths.

Action arguments declared with public?: false are meant to be set only by trusted server-side code (for example via Ash.Changeset.set_private_argument/3) and must not be settable from end-user input. CVE-2026-55736 fixed the non-bulk changeset path to strip private arguments from user-supplied parameter maps, but the bulk destroy and bulk update paths were not covered.

Ash.Actions.Destroy.Bulk.base_changeset/5 and Ash.Actions.Update.Bulk.base_changeset/5 match every key in the caller-supplied parameter map against all of the action's arguments with no public? check, then apply the matches to the base changeset. A caller who can submit parameters to a bulk destroy or bulk update action (for example through AshJsonApi, AshGraphql, or a controller that forwards request parameters to Ash.bulk_destroy/4 or Ash.bulk_update/4) can therefore set any private argument of that action, including one referenced by an arg(...) template in the action's changes or validations. Depending on how the application uses the argument (for example an acting_user_id driving authorization or record ownership, or audit metadata), this can lead to an integrity violation or privilege escalation.

The fix requires public? in the argument matching on both bulk paths; private arguments remain settable server-side via the :private_arguments option.

This issue affects ash: from 2.17.15 before 3.33.11.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.