eef-cve-2026-80218
CVSS 7.6 osv_hex
Description
## Summary Improper Authentication vulnerability in team-alembic AshAuthentication allows an attacker holding a sign-in token for one authenticated resource to be signed in as a user of a different resource. `AshAuthentication.Strategy.Password.SignInWithTokenPreparation.extract_primary_keys_from_subject/2` parses the JWT `sub` claim (for example `user?id=1`) with `URI.parse/1` and keeps only its query string, discarding the path segment that names the subject the token was issued for. Nothing else restores that binding: `AshAuthentication.Jwt.verify/3` checks the signature, `exp`, `nbf`, `jti` and the library-version claims, the purpose check only requires `sign_in`, and the remaining comparison is over primary-key field names, which are identical across resources. The WebAuthn sign-in and remember-me preparations carry copies of the same helper and drop the path in the same way. The magic link sign-in path pins the subject name against the resource and is not affected. This issue affects ash_authentication: from 3.10.5 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.
Timeline
- Published
- unknown
- Last Modified
- unknown
CVSS Details
CVSS details not available.
Affected Products
No product information available.
Weaknesses (CWE)
References
- https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-3pr8-f99q-86hp
- https://cna.erlef.org/cves/CVE-2026-80218.html
- https://github.com/team-alembic/ash_authentication/commit/eca8cadea0f1595ed2c10a0c177b1da9aa9e5269
- https://github.com/team-alembic/ash_authentication/commit/2640e1872e1fef4e4606e601bf00102cff784c03
- https://github.com/team-alembic/ash_authentication/commit/7baac243ca651eee127a84d672eee3fcff42e598
- https://hex.pm/packages/ash_authentication
Linked Vulnerabilities
No linked vulnerabilities found.
{
"affected": [
{
"database_specific": {
"source": "https://cna.erlef.org/osv/EEF-CVE-2026-80218.json"
},
"package": {
"ecosystem": "Hex",
"name": "ash_authentication",
"purl": "pkg:hex/ash_authentication"
},
"ranges": [
{
"events": [
{
"introduced": "3.10.5"
},
{
"fixed": "4.15.0"
}
],
"type": "SEMVER"
},
{
"events": [
{
"introduced": "5.0.0-rc.0"
},
{
"fixed": "5.0.0-rc.14"
}
],
"type": "SEMVER"
}
],
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"5.0.0-rc.11",
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"5.0.0-rc.13",
"5.0.0-rc.2",
"5.0.0-rc.3",
"5.0.0-rc.4",
"5.0.0-rc.5",
"5.0.0-rc.6",
"5.0.0-rc.7",
"5.0.0-rc.8",
"5.0.0-rc.9"
]
},
{
"database_specific": {
"source": "https://cna.erlef.org/osv/EEF-CVE-2026-80218.json"
},
"ranges": [
{
"events": [
{
"introduced": "eca8cadea0f1595ed2c10a0c177b1da9aa9e5269"
},
{
"fixed": "2640e1872e1fef4e4606e601bf00102cff784c03"
},
{
"fixed": "7baac243ca651eee127a84d672eee3fcff42e598"
}
],
"repo": "https://github.com/team-alembic/ash_authentication",
"type": "GIT"
}
],
"versions": [
"v4.14.2",
"v5.0.0-rc.13",
"v4.14.1",
"v5.0.0-rc.12",
"v5.0.0-rc.11",
"v5.0.0-rc.10",
"v4.14.0",
"v4.13.7",
"5.0.0-rc.9",
"5.0.0-rc.8",
"v5.0.0-rc.7",
"v5.0.0-rc.6",
"v5.0.0-rc.5",
"v5.0.0-rc.4",
"v5.0.0-rc.3",
"v5.0.0-rc.2",
"v5.0.0-rc.1",
"v5.0.0-rc.0",
"v4.13.6",
"v4.13.5",
"v4.13.4",
"v4.13.3",
"v4.13.2",
"v4.13.1",
"v4.13.0",
"v4.12.0",
"v4.11.0",
"v4.10.0",
"v4.9.9",
"v4.9.8",
"v4.9.7",
"v4.9.6",
"v4.9.5",
"v4.9.4",
"v4.9.3",
"v4.9.2",
"v4.9.1",
"v4.9.0",
"v4.8.7",
"v4.8.5",
"v4.8.4",
"v4.8.3",
"v4.8.2",
"v4.8.1",
"v4.8.0",
"v4.7.7",
"v4.7.6",
"v4.7.5",
"v4.7.4",
"v4.7.3",
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"v3.12.2",
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"v3.11.14",
"v3.11.13",
"v3.11.12",
"v3.11.10",
"v3.11.9",
"v3.11.8",
"v3.11.7",
"v3.11.6",
"v3.11.5",
"v3.11.4",
"v3.11.3",
"v3.11.2",
"v3.11.1",
"v3.11.0",
"v3.10.8",
"v3.10.7",
"v3.10.6",
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]
}
],
"aliases": [
"CVE-2026-80218",
"GHSA-3pr8-f99q-86hp"
],
"credits": [
{
"name": "Peter Ullrich",
"type": "REPORTER"
},
{
"name": "Jonatan Männchen / EEF",
"type": "ANALYST"
},
{
"name": "James Harton",
"type": "REMEDIATION_DEVELOPER"
}
],
"database_specific": {
"capec_ids": [
"CAPEC-151"
],
"cpe_ids": [
"cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*"
],
"cwe_ids": [
"CWE-287"
]
},
"details": "## Summary\n\nImproper Authentication vulnerability in team-alembic AshAuthentication allows an attacker holding a sign-in token for one authenticated resource to be signed in as a user of a different resource.\n\n`AshAuthentication.Strategy.Password.SignInWithTokenPreparation.extract_primary_keys_from_subject/2` parses the JWT `sub` claim (for example `user?id=1`) with `URI.parse/1` and keeps only its query string, discarding the path segment that names the subject the token was issued for. Nothing else restores that binding: `AshAuthentication.Jwt.verify/3` checks the signature, `exp`, `nbf`, `jti` and the library-version claims, the purpose check only requires `sign_in`, and the remaining comparison is over primary-key field names, which are identical across resources. The WebAuthn sign-in and remember-me preparations carry copies of the same helper and drop the path in the same way. The magic link sign-in path pins the subject name against the resource and is not affected.\n\nThis issue affects ash_authentication: from 3.10.5 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.",
"id": "EEF-CVE-2026-80218",
"modified": "2026-09-17T13:26:03.729128908Z",
"published": "2026-09-17T13:09:25.585Z",
"references": [
{
"type": "ADVISORY",
"url": "https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-3pr8-f99q-86hp"
},
{
"type": "WEB",
"url": "https://cna.erlef.org/cves/CVE-2026-80218.html"
},
{
"type": "WEB",
"url": "https://github.com/team-alembic/ash_authentication/commit/eca8cadea0f1595ed2c10a0c177b1da9aa9e5269"
},
{
"type": "FIX",
"url": "https://github.com/team-alembic/ash_authentication/commit/2640e1872e1fef4e4606e601bf00102cff784c03"
},
{
"type": "FIX",
"url": "https://github.com/team-alembic/ash_authentication/commit/7baac243ca651eee127a84d672eee3fcff42e598"
},
{
"type": "PACKAGE",
"url": "https://hex.pm/packages/ash_authentication"
}
],
"schema_version": "1.9.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Sign-in token minted for one resource accepted by another in AshAuthentication"
}