{"id":"CVE-2026-80218","title":"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.\n\nAshAuthentication.Strategy.Password.Sig…","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.\n\nAshAuthentication.Strategy.Password.Sig…","severity":"high","cvss":7.6,"cvssVector":"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","cwe":["CWE-287"],"vendor":"team-alembic","product":"ash_authentication","affected":["ash_authentication >= 3.10.5 < 4.15.0","ash_authentication >= 5.0.0-rc.0 < 5.0.0-rc.14","team-alembic/ash_authentication >= eca8cadea0f1595ed2c10a0c177b1da9aa9e5269 < *"],"published":"2026-09-17","updated":"2026-09-18","sourceUpdated":"2026-09-18T18:16:18.527","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-80218","references":[{"url":"https://cna.erlef.org/cves/CVE-2026-80218.html","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/team-alembic/ash_authentication/commit/2640e1872e1fef4e4606e601bf00102cff784c03","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/team-alembic/ash_authentication/commit/7baac243ca651eee127a84d672eee3fcff42e598","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/team-alembic/ash_authentication/commit/eca8cadea0f1595ed2c10a0c177b1da9aa9e5269","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-3pr8-f99q-86hp","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-80218","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}],"tags":["nvd","cve.org"],"epss":0.00454,"epssPercentile":0.38741,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-09-17T18:28:40.896413Z"},"cvssSource":"cna","ingestedAt":"2026-09-17T13:18:16.986Z","slug":"CVE-2026-80218","body":"## Overview\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\nAshAuthentication.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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":41.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}