FKIE_CVE-2026-88952
Vulnerability from fkie_nvd - Published: 2026-09-17 15:16 - Updated: 2026-09-17 20:18
Severity
Summary
Improper Authentication vulnerability in team-alembic AshAuthentication allows an attacker to be signed in as another user by linking an OAuth2 identity to an account that is not theirs.
AshAuthentication.Strategy.OAuth2.UserResolver.resolve/3 matches an existing account using the register action's upsert_identity keys, then gates linking the incoming provider identity to it on email_trusted?/2, which reads only the provider's email_verified boolean and never compares the provider's email value with the matched account's email. That gate assumes the account was matched by its email field, so under any other upsert_identity it is vacuous and an attacker presenting their own verified email is attached to, and issued a session for, an account matched on some other attribute. The same unguarded gate applies in OAuth2.SignInPreparation on the registration_enabled? false path, where the account is matched by the sign-in action's read filter instead. The upsert also rewrites the matched account's email to the attacker's address, so later account recovery reaches the attacker rather than the owner.
This issue affects ash_authentication: from 4.14.0 before 4.15.0 and from 5.0.0-rc.10 before 5.0.0-rc.14.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"collectionURL": "https://repo.hex.pm",
"cpes": [
"cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027",
"\u0027Elixir.AshAuthentication.Strategy.OAuth2.SignInPreparation\u0027",
"\u0027Elixir.AshAuthentication.Strategy.OAuth2.IdentityChange\u0027",
"\u0027Elixir.AshAuthentication.Strategy.DynamicOidc.IdentityChange\u0027"
],
"packageName": "ash_authentication",
"packageURL": "pkg:hex/ash_authentication",
"product": "ash_authentication",
"programFiles": [
"lib/ash_authentication/strategies/oauth2/user_resolver.ex",
"lib/ash_authentication/strategies/oauth2/sign_in_preparation.ex",
"lib/ash_authentication/strategies/oauth2/identity_change.ex",
"lib/ash_authentication/strategies/dynamic_oidc/identity_change.ex"
],
"programRoutines": [
{
"name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027:resolve/3"
},
{
"name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027:email_trusted?/2"
},
{
"name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.SignInPreparation\u0027:prepare/3"
},
{
"name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.IdentityChange\u0027:change/3"
},
{
"name": "\u0027Elixir.AshAuthentication.Strategy.DynamicOidc.IdentityChange\u0027:change/3"
}
],
"repo": "https://github.com/team-alembic/ash_authentication",
"vendor": "team-alembic",
"versions": [
{
"lessThan": "4.15.0",
"status": "affected",
"version": "4.14.0",
"versionType": "semver"
},
{
"lessThan": "5.0.0-rc.14",
"status": "affected",
"version": "5.0.0-rc.10",
"versionType": "semver"
}
]
},
{
"collectionURL": "https://github.com",
"cpes": [
"cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027",
"\u0027Elixir.AshAuthentication.Strategy.OAuth2.SignInPreparation\u0027",
"\u0027Elixir.AshAuthentication.Strategy.OAuth2.IdentityChange\u0027",
"\u0027Elixir.AshAuthentication.Strategy.DynamicOidc.IdentityChange\u0027"
],
"packageName": "team-alembic/ash_authentication",
"packageURL": "pkg:github/team-alembic/ash_authentication",
"product": "ash_authentication",
"programFiles": [
"lib/ash_authentication/strategies/oauth2/user_resolver.ex",
"lib/ash_authentication/strategies/oauth2/sign_in_preparation.ex",
"lib/ash_authentication/strategies/oauth2/identity_change.ex",
"lib/ash_authentication/strategies/dynamic_oidc/identity_change.ex"
],
"programRoutines": [
{
"name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027:resolve/3"
},
{
"name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027:email_trusted?/2"
},
{
"name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.SignInPreparation\u0027:prepare/3"
},
{
"name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.IdentityChange\u0027:change/3"
},
{
"name": "\u0027Elixir.AshAuthentication.Strategy.DynamicOidc.IdentityChange\u0027:change/3"
}
],
"repo": "https://github.com/team-alembic/ash_authentication",
"vendor": "team-alembic",
"versions": [
{
"changes": [
{
"at": "738bf9f32f2aa0d1bb92ce9ca5c2476cb5710459",
"status": "unaffected"
},
{
"at": "2bd630eef8b7c8ae1e90e8fd43ba12fbc7e256ba",
"status": "unaffected"
}
],
"lessThan": "*",
"status": "affected",
"version": "64530644f9b37ebb76ca14aeb83a77597a0034b7",
"versionType": "git"
},
{
"changes": [
{
"at": "738bf9f32f2aa0d1bb92ce9ca5c2476cb5710459",
"status": "unaffected"
},
{
"at": "2bd630eef8b7c8ae1e90e8fd43ba12fbc7e256ba",
"status": "unaffected"
}
],
"lessThan": "*",
"status": "affected",
"version": "42edcd8ebb13fafbb168f12591d7518ce0611fec",
"versionType": "git"
}
]
}
],
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Improper Authentication vulnerability in team-alembic AshAuthentication allows an attacker to be signed in as another user by linking an OAuth2 identity to an account that is not theirs.\n\nAshAuthentication.Strategy.OAuth2.UserResolver.resolve/3 matches an existing account using the register action\u0027s upsert_identity keys, then gates linking the incoming provider identity to it on email_trusted?/2, which reads only the provider\u0027s email_verified boolean and never compares the provider\u0027s email value with the matched account\u0027s email. That gate assumes the account was matched by its email field, so under any other upsert_identity it is vacuous and an attacker presenting their own verified email is attached to, and issued a session for, an account matched on some other attribute. The same unguarded gate applies in OAuth2.SignInPreparation on the registration_enabled? false path, where the account is matched by the sign-in action\u0027s read filter instead. The upsert also rewrites the matched account\u0027s email to the attacker\u0027s address, so later account recovery reaches the attacker rather than the owner.\n\nThis issue affects ash_authentication: from 4.14.0 before 4.15.0 and from 5.0.0-rc.10 before 5.0.0-rc.14."
}
],
"id": "CVE-2026-88952",
"lastModified": "2026-09-17T20:18:51.800",
"metrics": {
"cvssMetricV40": [
{
"cvssData": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"availabilityRequirement": "NOT_DEFINED",
"baseScore": 9.1,
"baseSeverity": "CRITICAL",
"confidentialityRequirement": "NOT_DEFINED",
"exploitMaturity": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "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",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-88952",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-09-17T19:32:22.090404Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-09-17T15:16:56.290",
"references": [
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://cna.erlef.org/cves/CVE-2026-88952.html"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/team-alembic/ash_authentication/commit/2bd630eef8b7c8ae1e90e8fd43ba12fbc7e256ba"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/team-alembic/ash_authentication/commit/42edcd8ebb13fafbb168f12591d7518ce0611fec"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/team-alembic/ash_authentication/commit/64530644f9b37ebb76ca14aeb83a77597a0034b7"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/team-alembic/ash_authentication/commit/738bf9f32f2aa0d1bb92ce9ca5c2476cb5710459"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-wc6x-276q-jrf9"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://osv.dev/vulnerability/EEF-CVE-2026-88952"
}
],
"sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"vulnStatus": "Received",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-287"
}
],
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"type": "Secondary"
}
]
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…