{"id":"CVE-2026-75757","summary":"AshAdmin cookie reader matches names by substring, enabling actor/session shadowing from a sibling subdomain","details":"Reliance on Cookies without Validation and Integrity Checking vulnerability in ash-project ash_admin lets an attacker who controls a sibling subdomain rebind an admin's session to a different actor, tenant, or authorization mode.\n\nAshAdmin's client JavaScript read its state cookies (tenant, actor_resource, actor_primary_key, actor_action, actor_domain, actor_authorizing, actor_paused) by matching the cookie name with an unanchored regular expression (new RegExp(name + \"=([^;]+)\")) against the whole document.cookie. Any cookie whose name merely ends with the requested name therefore matches, and whichever is serialized first wins. Because cookies are shared across a registrable domain, a compromised sibling subdomain can set a shadowing cookie (for example xactor_authorizing) with Domain=.example.com that flows unvalidated into the admin's LiveSocket connect params. The fix matches cookie names by exact equality.\n\nThis issue affects ash_admin: from 0.9.1 before 1.3.1.","aliases":["EEF-CVE-2026-75757","GHSA-3259-55fp-w94j"],"modified":"2026-09-01T03:46:12.267782783Z","published":"2026-08-31T02:20:17.985Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75757.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"77a43cc4fa04cb59c38fc434568a35a38ecb995a"},{"fixed":"e93a3408a85035e1f90275d02bc2470c96095e56"}]}],"cna_assigner":"EEF","cwe_ids":["CWE-565"]},"references":[{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-75757.html"},{"type":"WEB","url":"https://github.com"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-75757"},{"type":"WEB","url":"https://repo.hex.pm"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75757.json"},{"type":"ADVISORY","url":"https://github.com/ash-project/ash_admin/security/advisories/GHSA-3259-55fp-w94j"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-75757"},{"type":"FIX","url":"https://github.com/ash-project/ash_admin/commit/e93a3408a85035e1f90275d02bc2470c96095e56"},{"type":"PACKAGE","url":"https://github.com/ash-project/ash_admin"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/ash-project/ash_admin","events":[{"introduced":"9297612f82dc03585f65b9e1b0eba72a74b0751f"},{"fixed":"91da87c1c23cd6199ba1b0a1c8849a4c605130cc"},{"fixed":"e93a3408a85035e1f90275d02bc2470c96095e56"}],"database_specific":{"extracted_events":[{"introduced":"0.9.1"},{"fixed":"1.3.1"}],"source":["DESCRIPTION","REFERENCES"]}}],"versions":["v1.3.0","v1.2.0","v1.1.0","v0.14.0","v0.13.26","v0.13.25","v0.13.24","v0.13.23","v0.13.22","v0.13.21","v0.13.20","v0.13.19","v0.13.18","v0.13.17","v0.13.16","v0.13.15","v0.13.14","v0.13.13","v0.13.12","v0.13.11","v0.13.10","v0.13.9","v0.13.8","v0.13.7","v0.13.6","v0.13.5","v0.13.4","v0.13.3","v0.13.2","v0.13.0","v0.12.6","v0.12.5","v0.12.4","v0.12.3","v0.12.2","v0.12.1","v0.12.0","v0.11.11","v0.11.10","v0.11.9","v0.11.8","v0.11.7","v0.11.6","v0.11.4","v0.11.3","v0.11.2","v0.11.1","v0.10.10","v0.10.10-rc.1","v0.10.10-rc.0","v0.10.9","v0.10.8","v0.10.7","v0.10.6","v0.10.5","v0.10.4","v0.10.3","v0.10.2","v0.10.1","v0.10.0","v0.9.8","v0.9.7","v0.9.6","v0.9.5","v0.9.4","v0.9.2","v0.9.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-75757.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N"}]}