Private action arguments can be set by user input on the bulk destroy and bulk update paths in Ash

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-93477
StatePUBLISHED
AssignerEEF
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-25 07:16:56 UTC
Updated2026-09-25 07:16:56 UTC
DescriptionImproperly 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.

Risk And Classification

Primary CVSS: v4.0 5.9 MEDIUM from 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Problem Types: CWE-915 | CWE-915 CWE-915 Improperly Controlled Modification of Dynamically-Determined Object Attributes

VersionSourceTypeScoreSeverityVector
4.06b3ad84c-e1a6-4bf7-a703-f496b71e49dbSecondary5.9MEDIUMCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS5.9MEDIUMCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Local
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
High
Availability
None
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Ash-project Ash affected 2.17.15 3.33.11 semver Not specified
CNA Ash-project Ash affected 8c17434803b2e91de522bdfbd0ca918e5d5898df 6b7ac53a0a2532291eb940d7beaf0fbb2da6fc4f git Not specified

References

ReferenceSourceLinkTags
cna.erlef.org/cves/CVE-2026-93477.html 6b3ad84c-e1a6-4bf7-a703-f496b71e49db cna.erlef.org
osv.dev/vulnerability/EEF-CVE-2026-93477 6b3ad84c-e1a6-4bf7-a703-f496b71e49db osv.dev
github.com/ash-project/ash/security/advisories/GHSA-c2p4-p7q6-hr2j 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
github.com/ash-project/ash/commit/6b7ac53a0a2532291eb940d7beaf0fbb2da6fc4f 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
github.com/ash-project/ash/commit/8c17434803b2e91de522bdfbd0ca918e5d5898df 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: zx (en)

CNA: zx (en)

CNA: Zach Daniel / Ash Project (en)

CNA: Jonatan Männchen / EEF (en)

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