{"api_version":"1","generated_at":"2026-08-31T03:53:52+00:00","cve":"CVE-2026-75757","urls":{"html":"https://cve.report/CVE-2026-75757","api":"https://cve.report/api/cve/CVE-2026-75757.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-75757","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-75757"},"summary":{"title":"AshAdmin cookie reader matches names by substring, enabling actor/session shadowing from a sibling subdomain","description":"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. 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The fix matches cookie names by exact equality.</p>\n<p>This issue affects ash_admin: from 0.9.1 before 1.3.1.</p>"},{"base64":false,"type":"text/markdown","value":"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."}],"value":"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."}],"impacts":[{"capecId":"CAPEC-31","descriptions":[{"lang":"en","value":"CAPEC-31 Accessing/Intercepting/Modifying HTTP Cookies"}]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":8.3,"baseSeverity":"HIGH","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:L/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-565","description":"CWE-565 Reliance on Cookies without Validation and Integrity Checking","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-31T02:20:17.985Z","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","shortName":"EEF"},"references":[{"tags":["vendor-advisory","related"],"url":"https://github.com/ash-project/ash_admin/security/advisories/GHSA-3259-55fp-w94j"},{"tags":["related"],"url":"https://cna.erlef.org/cves/CVE-2026-75757.html"},{"tags":["related"],"url":"https://osv.dev/vulnerability/EEF-CVE-2026-75757"},{"tags":["patch"],"url":"https://github.com/ash-project/ash_admin/commit/e93a3408a85035e1f90275d02bc2470c96095e56"}],"source":{"discovery":"EXTERNAL"},"title":"AshAdmin cookie reader matches names by substring, enabling actor/session shadowing from a sibling subdomain"}},"cveMetadata":{"assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","assignerShortName":"EEF","cveId":"CVE-2026-75757","datePublished":"2026-08-31T02:20:17.985Z","dateReserved":"2026-08-30T23:30:01.239Z","dateUpdated":"2026-08-31T02:20:17.985Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-31 03:16:42","lastModifiedDate":"2026-08-31 03:16:42","problem_types":["CWE-565","CWE-565 CWE-565 Reliance on Cookies without Validation and Integrity Checking"],"metrics":{"cvssMetricV40":[{"source":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","type":"Secondary","cvssData":{"version":"4.0","vectorString":"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/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","baseScore":8.3,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"75757","Ordinal":"1","Title":"AshAdmin cookie reader matches names by substring, enabling acto","CVE":"CVE-2026-75757","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"75757","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"AshAdmin cookie reader matches names by substring, enabling acto"}]}}}