next-auth · Vulnerability
cve-program · CVE-2026-73421
PublishedNextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js has a server configuration error. In middleware, Route Handlers, React Server Components, and other auth() entry points, a non-OK session response is parsed into a truthy error object instead of null, so checks such as !!auth and if (req.auth) evaluate to true for unauthenticated requests. A provider missing both the issuer and authorization endpoint triggers InvalidEndpoints, and an unset AUTH_SECRET or another server configuration error can produce the same behavior. There is no impact while configuration is valid, but after a deployment becomes misconfigured, routes protected only by session existence silently grant access to every visitor. This issue is fixed in next-auth 5.0.0-beta.32.
Read the publisher's advisoryeuvd · EUVD-2026-58523
PublishedNextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js has a server configuration error. In middleware, Route Handlers, React Server Components, and other auth() entry points, a non-OK session response is parsed into a truthy error object instead of null, so checks such as !!auth and if (req.auth) evaluate to true for unauthenticated requests. A provider missing both the issuer and authorization endpoint triggers InvalidEndpoints, and an unset AUTH_SECRET or another server configuration error can produce the same behavior. There is no impact while configuration is valid, but after a deployment becomes misconfigured, routes protected only by session existence silently grant access to every visitor. This issue is fixed in next-auth 5.0.0-beta.32.
Read the publisher's advisorynvd · CVE-2026-73421
PublishedNextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js has a server configuration error. In middleware, Route Handlers, React Server Components, and other auth() entry points, a non-OK session response is parsed into a truthy error object instead of null, so checks such as !!auth and if (req.auth) evaluate to true for unauthenticated requests. A provider missing both the issuer and authorization endpoint triggers InvalidEndpoints, and an unset AUTH_SECRET or another server configuration error can produce the same behavior. There is no impact while configuration is valid, but after a deployment becomes misconfigured, routes protected only by session existence silently grant access to every visitor. This issue is fixed in next-auth 5.0.0-beta.32.
Read the publisher's advisoryosv · GHSA-8fpg-xm3f-6cx3
Published### Impact `next-auth` (Auth.js) v5 applications that gate access by checking only for the **existence** of the `auth` object — the pattern shown in the official [session management / protecting resources guide](https://authjs.dev/getting-started/session-management/protecting) — are affected. When the Auth.js configuration produces a server-side error, the `auth` object exposed by the `auth()` wrapper (in middleware, Route Handlers, etc.) is **populated with an error object instead of being `null`**: ```json { "message": "There was a problem with the server configuration. Check the server logs for more information." } ``` Because this object is truthy, any authorization check of the form `!!auth` (or `if (req.auth)`) evaluates to `true` for **every** request, including unauthenticated ones. The application *fails open*: instead of denying access when the auth layer is broken, it grants access to everyone. ```ts // middleware.ts — affected pattern export default auth((req) => { const { nextUrl, auth } = req const isLoggedIn = !!auth // <-- always true when the configuration is broken // ... }) ``` A representative trigger is a provider that is missing required configuration. For example, a Keycloak provider with neither `issuer` nor `authorization` endpoint set logs: ``` [auth][error] InvalidEndpoints: Provider "keycloak" is missing both `issuer` and `authorization` endpoint config. At least one of them is required. ``` …and from that point on `auth` is the error object above, so `!!auth` is permanently `true`. The same fail-open behavior occurs for other server-configuration errors (for example, an unset `AUTH_SECRET`). There is **no impact while the configuration is valid**. The risk materializes when a previously-working deployment becomes misconfigured — e.g. an environment variable is changed or removed during a deploy — at which point existence-based auth checks silently stop protecting routes and all visitors are treated as authenticated. Because the failure mode is silent and grants access to everyone, the consequences can be severe. This is an instance of CWE-636 (Not Failing Securely / "Failing Open") leading to improper authorization (CWE-285). ### Patches The fix ensures that a server-configuration error no longer surfaces as a truthy `auth` object: existence checks fail **closed** rather than open. This is released in `next-auth@<!-- TODO: set patched version on publish -->`. To upgrade: ```sh npm i next-auth@beta ``` ```sh yarn add next-auth@beta ``` ```sh pnpm add next-auth@beta ``` ### Workarounds If you cannot upgrade immediately, check for a concrete user/session property rather than the bare object, so a configuration-error object is not treated as an authenticated session: ```ts // middleware.ts export default auth((req) => { // `auth.user` is only present on a real session; resilient to config-error objects const isLoggedIn = !!req.auth?.user // ... }) ``` As defense in depth, make Auth.js configuration errors fail loudly in your deployment pipeline (for example, treat `[auth][error]` log lines as a failed health check) so a broken configuration cannot silently reach production. As always, an existing session indicates authentication only — for authorization, perform an explicit role/permission check rather than relying on session existence. See the [role-based access control guide](https://authjs.dev/guides/role-based-access-control). ### References - Protecting resources / session management: https://authjs.dev/getting-started/session-management/protecting - Role-based access control (RBAC): https://authjs.dev/guides/role-based-access-control - Auth.js error reference: https://authjs.dev/reference/core/errors ### For more information If you have any concerns, Auth.js requests responsible disclosure, outlined here: https://authjs.dev/security ### Credits Reported by @marc-zollingkoffer-syzygy.
Read the publisher's advisoryAffected versions, risk and source history
Exploitation and risk
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cve-program · CVE-2026-73421
PublishedNextAuth.js: Configuration errors can cause existence-based auth checks to fail open (auth object populated with an error)
NextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js has a server configuration error. In middleware, Route Handlers, React Server Components, and other auth() entry points, a non-OK session response is parsed into a truthy error object instead of null, so checks such as !!auth and if (req.auth) evaluate to true for unauthenticated requests. A provider missing both the issuer and authorization endpoint triggers InvalidEndpoints, and an unset AUTH_SECRET or another server configuration error can produce the same behavior. There is no impact while configuration is valid, but after a deployment becomes misconfigured, routes protected only by session existence silently grant access to every visitor. This issue is fixed in next-auth 5.0.0-beta.32.
- Source published
- 13 Aug 2026 22:04:36 UTC
- Source modified
- 18 Aug 2026 01:45:41 UTC
- Saved here
- 23 Oct 2026 15:48:27 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
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CVSS 4.0 · 9.1 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
euvd · EUVD-2026-58523
PublishedNextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js …
NextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js has a server configuration error. In middleware, Route Handlers, React Server Components, and other auth() entry points, a non-OK session response is parsed into a truthy error object instead of null, so checks such as !!auth and if (req.auth) evaluate to true for unauthenticated requests. A provider missing both the issuer and authorization endpoint triggers InvalidEndpoints, and an unset AUTH_SECRET or another server configuration error can produce the same behavior. There is no impact while configuration is valid, but after a deployment becomes misconfigured, routes protected only by session existence silently grant access to every visitor. This issue is fixed in next-auth 5.0.0-beta.32.
Additional publisher context
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Aug 13, 2026, 10:04:36 PM
dateUpdated: Aug 18, 2026, 1:45:41 AM
- Source published
- Aug 13, 2026, 10:04:36 PM (timezone not stated)
- Source modified
- Aug 18, 2026, 1:45:41 AM (timezone not stated)
- Saved here
- 11 Nov 2026 16:05:23 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
Source: euvd · ENISA EUVD · source terms and attribution apply. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
EUVD CVSS 4.0 · 9.1 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
nvd · CVE-2026-73421
PublishedNextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js …
NextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js has a server configuration error. In middleware, Route Handlers, React Server Components, and other auth() entry points, a non-OK session response is parsed into a truthy error object instead of null, so checks such as !!auth and if (req.auth) evaluate to true for unauthenticated requests. A provider missing both the issuer and authorization endpoint triggers InvalidEndpoints, and an unset AUTH_SECRET or another server configuration error can produce the same behavior. There is no impact while configuration is valid, but after a deployment becomes misconfigured, routes protected only by session existence silently grant access to every visitor. This issue is fixed in next-auth 5.0.0-beta.32.
Additional publisher context
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Awaiting Analysis
Weakness classifications: CWE-285 · CWE-636
Original publisher date fields
published: 2026-08-13T22:17:26.447
lastModified: 2026-09-18T20:05:53.723
- Source published
- 13 Aug 2026 22:17:26 UTC
- Source modified
- 18 Sep 2026 20:05:53 UTC
- Saved here
- 25 Oct 2026 15:19:09 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
Source: nvd · NIST NVD usage terms; underlying source attribution retained. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 4.0 · [email protected] · Secondary · 9.1 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
osv · GHSA-8fpg-xm3f-6cx3
PublishedAuth.js: Configuration errors can cause existence-based auth checks to fail open (auth object populated with an error)
### Impact `next-auth` (Auth.js) v5 applications that gate access by checking only for the **existence** of the `auth` object — the pattern shown in the official [session management / protecting resources guide](https://authjs.dev/getting-started/session-management/protecting) — are affected. When the Auth.js configuration produces a server-side error, the `auth` object exposed by the `auth()` wrapper (in middleware, Route Handlers, etc.) is **populated with an error object instead of being `null`**: ```json { "message": "There was a problem with the server configuration. Check the server logs for more information." } ``` Because this object is truthy, any authorization check of the form `!!auth` (or `if (req.auth)`) evaluates to `true` for **every** request, including unauthenticated ones. The application *fails open*: instead of denying access when the auth layer is broken, it grants access to everyone. ```ts // middleware.ts — affected pattern export default auth((req) => { const { nextUrl, auth } = req const isLoggedIn = !!auth // <-- always true when the configuration is broken // ... }) ``` A representative trigger is a provider that is missing required configuration. For example, a Keycloak provider with neither `issuer` nor `authorization` endpoint set logs: ``` [auth][error] InvalidEndpoints: Provider "keycloak" is missing both `issuer` and `authorization` endpoint config. At least one of them is required. ``` …and from that point on `auth` is the error object above, so `!!auth` is permanently `true`. The same fail-open behavior occurs for other server-configuration errors (for example, an unset `AUTH_SECRET`). There is **no impact while the configuration is valid**. The risk materializes when a previously-working deployment becomes misconfigured — e.g. an environment variable is changed or removed during a deploy — at which point existence-based auth checks silently stop protecting routes and all visitors are treated as authenticated. Because the failure mode is silent and grants access to everyone, the consequences can be severe. This is an instance of CWE-636 (Not Failing Securely / "Failing Open") leading to improper authorization (CWE-285). ### Patches The fix ensures that a server-configuration error no longer surfaces as a truthy `auth` object: existence checks fail **closed** rather than open. This is released in `next-auth@<!-- TODO: set patched version on publish -->`. To upgrade: ```sh npm i next-auth@beta ``` ```sh yarn add next-auth@beta ``` ```sh pnpm add next-auth@beta ``` ### Workarounds If you cannot upgrade immediately, check for a concrete user/session property rather than the bare object, so a configuration-error object is not treated as an authenticated session: ```ts // middleware.ts export default auth((req) => { // `auth.user` is only present on a real session; resilient to config-error objects const isLoggedIn = !!req.auth?.user // ... }) ``` As defense in depth, make Auth.js configuration errors fail loudly in your deployment pipeline (for example, treat `[auth][error]` log lines as a failed health check) so a broken configuration cannot silently reach production. As always, an existing session indicates authentication only — for authorization, perform an explicit role/permission check rather than relying on session existence. See the [role-based access control guide](https://authjs.dev/guides/role-based-access-control). ### References - Protecting resources / session management: https://authjs.dev/getting-started/session-management/protecting - Role-based access control (RBAC): https://authjs.dev/guides/role-based-access-control - Auth.js error reference: https://authjs.dev/reference/core/errors ### For more information If you have any concerns, Auth.js requests responsible disclosure, outlined here: https://authjs.dev/security ### Credits Reported by @marc-zollingkoffer-syzygy.
- Source published
- 23 Jul 2026 14:52:23 UTC
- Source modified
- 12 Aug 2026 20:56:01 UTC
- Saved here
- 24 Oct 2026 13:17:17 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
Original source record · Cite this exact observation · Complete original publisher JSON
Source: osv · GitHub Advisory Database · CC-BY-4.0. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS_V4 · 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
Publisher rating · CRITICAL