{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-73420", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-08-12T14:32:11.795Z", "datePublished": "2026-08-13T22:04:15.414Z", "dateUpdated": "2026-08-13T22:04:15.414Z"}, "containers": {"cna": {"title": "NextAuth.js: Email normalizer validates the address before Unicode normalization, allowing a homoglyph @ bypass", "problemTypes": [{"descriptions": [{"cweId": "CWE-180", "lang": "en", "description": "CWE-180: Incorrect Behavior Order: Validate Before Canonicalize", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 9.1, "baseSeverity": "CRITICAL", "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", "version": "4.0"}}], "references": [{"name": "https://github.com/nextauthjs/next-auth/security/advisories/GHSA-7rqj-j65f-68wh", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/nextauthjs/next-auth/security/advisories/GHSA-7rqj-j65f-68wh"}, {"name": "https://github.com/nextauthjs/next-auth/commit/19d2feb24359fa8c79418907fc68d9ec8152ca94", "tags": ["x_refsource_MISC"], "url": "https://github.com/nextauthjs/next-auth/commit/19d2feb24359fa8c79418907fc68d9ec8152ca94"}, {"name": "https://github.com/nextauthjs/next-auth/commit/a63eee12a1a20cb35209e44195b097868517b9a0", "tags": ["x_refsource_MISC"], "url": "https://github.com/nextauthjs/next-auth/commit/a63eee12a1a20cb35209e44195b097868517b9a0"}, {"name": "https://github.com/nextauthjs/next-auth/releases/tag/@auth/core@0.41.3", "tags": ["x_refsource_MISC"], "url": "https://github.com/nextauthjs/next-auth/releases/tag/@auth/core@0.41.3"}, {"name": "https://github.com/nextauthjs/next-auth/releases/tag/next-auth@4.24.15", "tags": ["x_refsource_MISC"], "url": "https://github.com/nextauthjs/next-auth/releases/tag/next-auth@4.24.15"}, {"name": "https://github.com/nextauthjs/next-auth/releases/tag/next-auth@5.0.0-beta.32", "tags": ["x_refsource_MISC"], "url": "https://github.com/nextauthjs/next-auth/releases/tag/next-auth@5.0.0-beta.32"}], "affected": [{"vendor": "nextauthjs", "product": "next-auth", "versions": [{"version": "< 4.24.15", "status": "affected"}, {"version": ">= 5.0.0-beta.4, < 5.0.0-beta.32", "status": "affected"}]}, {"vendor": "@auth", "product": "core", "versions": [{"version": ">= 0.1.0, < 0.41.3", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-13T22:04:15.414Z"}, "descriptions": [{"lang": "en", "value": "NextAuth.js provides authentication for Next.js. Prior to @auth/core 0.41.3 and next-auth 4.24.15 and 5.0.0-beta.32, the defaultNormalizer used by the email and magic-link sign-in flow validates an address before applying Unicode normalization. An address can contain a Unicode character such as U+FF20 FULLWIDTH COMMERCIAL AT that is not ASCII at-sign but canonicalizes to an ASCII at-sign under NFKC or NFKD normalization. The address passes the normalizer's single-at-sign check, but a downstream sendVerificationRequest mail library or delivery service that normalizes the address can then see two at-sign separators and deliver the passwordless sign-in link to an attacker-controlled recipient. Applications are affected when the email provider uses the built-in normalizer rather than a custom normalizeIdentifier and the downstream sender applies Unicode normalization. An attacker who knows a victim's email address can request the misrouted magic link and sign in as the victim without victim interaction. This issue is fixed in @auth/core 0.41.3 and next-auth 4.24.15 and 5.0.0-beta.32."}], "source": {"advisory": "GHSA-7rqj-j65f-68wh", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "next-auth", "vendor": "nextauthjs", "versions": [{"status": "affected", "version": "< 4.24.15"}, {"status": "affected", "version": ">= 5.0.0-beta.4, < 5.0.0-beta.32"}]}, {"product": "core", "vendor": "@auth", "versions": [{"status": "affected", "version": ">= 0.1.0, < 0.41.3"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "NextAuth.js provides authentication for Next.js. Prior to @auth/core 0.41.3 and next-auth 4.24.15 and 5.0.0-beta.32, the defaultNormalizer used by the email and magic-link sign-in flow validates an address before applying Unicode normalization. An address can contain a Unicode character such as U+FF20 FULLWIDTH COMMERCIAL AT that is not ASCII at-sign but canonicalizes to an ASCII at-sign under NFKC or NFKD normalization. The address passes the normalizer's single-at-sign check, but a downstream sendVerificationRequest mail library or delivery service that normalizes the address can then see two at-sign separators and deliver the passwordless sign-in link to an attacker-controlled recipient. Applications are affected when the email provider uses the built-in normalizer rather than a custom normalizeIdentifier and the downstream sender applies Unicode normalization. An attacker who knows a victim's email address can request the misrouted magic link and sign in as the victim without victim interaction. This issue is fixed in @auth/core 0.41.3 and next-auth 4.24.15 and 5.0.0-beta.32."}], "id": "CVE-2026-73420", "lastModified": "2026-08-13T22:17:26.297", "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": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-08-13T22:17:26.297", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/nextauthjs/next-auth/commit/19d2feb24359fa8c79418907fc68d9ec8152ca94"}, {"source": "security-advisories@github.com", "url": "https://github.com/nextauthjs/next-auth/commit/a63eee12a1a20cb35209e44195b097868517b9a0"}, {"source": "security-advisories@github.com", "url": "https://github.com/nextauthjs/next-auth/releases/tag/@auth/core@0.41.3"}, {"source": "security-advisories@github.com", "url": "https://github.com/nextauthjs/next-auth/releases/tag/next-auth@4.24.15"}, {"source": "security-advisories@github.com", "url": "https://github.com/nextauthjs/next-auth/releases/tag/next-auth@5.0.0-beta.32"}, {"source": "security-advisories@github.com", "url": "https://github.com/nextauthjs/next-auth/security/advisories/GHSA-7rqj-j65f-68wh"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-180"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}