`require_confirmed_with` is not enforced on the action and fails open on an unreadable attribute in AshAuthentication

Summary

CVECVE-2026-85500
StatePUBLISHED
AssignerEEF
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-17 14:17:46 UTC
Updated2026-09-17 19:17:05 UTC
DescriptionAuthentication Bypass by Primary Weakness vulnerability in team-alembic AshAuthentication allows an unconfirmed user to obtain a session, defeating a mandatory email confirmation requirement. AshAuthentication.Strategy.Password.Actions.check_user/2 decides whether the attribute named by require_confirmed_with is set using a bare is_nil(Map.get(user, value)). When that attribute is not selected on the loaded record Map.get/2 returns %Ash.NotLoaded{}, and when a field policy denies it for the current actor it returns %Ash.ForbiddenField{}. Neither is nil, so the rejection branch is skipped and sign-i require_confirmed_with is enforced in two places, and neither holds in every configuration. sign_in_with_token and register are checked only inside AshAuthentication.Strategy.Password.Actions, not on the action itself, so any caller that invokes the action directly skips the check. An API layer such as AshGraphql or AshJsonApi invokes the action directly, so this applies to the default configuration. Where a check does run it compares the confirmation attribute against nil. That attribute holds %Ash.NotLoaded{} or %Ash.ForbiddenField{} when it sets select_by_default?: false, when an API layer narrows the read's select, or when a field policy hides it from the sign-in actor. Neither struct is nil, so those configurations read every user as confirmed. This issue affects ash_authentication: from 4.3.8 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.

Risk And Classification

Primary CVSS: v4.0 9.1 CRITICAL from 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/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-305 | CWE-305 CWE-305 Authentication Bypass by Primary Weakness


VersionSourceTypeScoreSeverityVector
4.06b3ad84c-e1a6-4bf7-a703-f496b71e49dbSecondary9.1CRITICALCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS9.1CRITICALCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

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

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/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 Team-alembic Ash Authentication affected 4.3.8 4.15.0 semver Not specified
CNA Team-alembic Ash Authentication affected 5.0.0-rc.0 5.0.0-rc.14 semver Not specified
CNA Team-alembic Ash Authentication affected 7d37bc6e4df6697b5813d2f373f0fdb08f813f98 * git Not specified

References

ReferenceSourceLinkTags
github.com/team-alembic/ash_authentication/commit/17f4c25a372d1778c9cc45... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
github.com/team-alembic/ash_authentication/commit/1076639a9d40213088d110... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
cna.erlef.org/cves/CVE-2026-85500.html 6b3ad84c-e1a6-4bf7-a703-f496b71e49db cna.erlef.org
github.com/team-alembic/ash_authentication/commit/7d37bc6e4df6697b5813d2... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
osv.dev/vulnerability/EEF-CVE-2026-85500 6b3ad84c-e1a6-4bf7-a703-f496b71e49db osv.dev
github.com/team-alembic/ash_authentication/security/advisories/GHSA-fc47... 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: Peter Ullrich (en)

CNA: Jonatan Männchen / EEF (en)

CNA: James Harton (en)

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