CVE-2026-73418
NextAuth.js: getToken() throws an uncaught exception on malformed Bearer authorization headers
Description
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 exported getToken() helper in the next-auth/jwt and @auth/core/jwt modules can throw an uncaught exception when it reads a malformed Authorization: Bearer header. When no session cookie is present, getToken() URL-decodes the bearer value before validating it, and malformed percent encoding causes decodeURIComponent() to throw instead of treating the token as invalid. Because getToken() is commonly called in API routes, middleware, and server-side request handlers, a single unauthenticated request can trigger an unhandled exception in code paths that authenticate requests, causing a per-request denial of service without exposing tokens, sessions, or other data and without bypassing authentication. This issue is fixed in @auth/core 0.41.3 and next-auth 4.24.15 and 5.0.0-beta.32.
INFO
Published Date :
Aug. 12, 2026, 9:17 p.m.
Last Modified :
Aug. 12, 2026, 9:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-73418
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update next-auth to version 4.24.15 or higher.
- Update next-auth to version 5.0.0-beta.32 or higher.
- Update @auth/core to version 0.41.3 or higher.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-73418.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-73418 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-73418
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-73418 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-73418 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Aug. 12, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'nextauthjs', 'product': 'next-auth', 'versions': [{'status': 'affected', 'version': '>= 4.0.6, <= 4.24.14'}, {'status': 'affected', 'version': '>= 5.0.0-beta.0, <= 5.0.0-beta.31'}]}, {'vendor': '@auth', 'product': 'core', 'versions': [{'status': 'affected', 'version': '>= 0.1.0, < 0.41.3'}]}] Added Description 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 exported getToken() helper in the next-auth/jwt and @auth/core/jwt modules can throw an uncaught exception when it reads a malformed Authorization: Bearer header. When no session cookie is present, getToken() URL-decodes the bearer value before validating it, and malformed percent encoding causes decodeURIComponent() to throw instead of treating the token as invalid. Because getToken() is commonly called in API routes, middleware, and server-side request handlers, a single unauthenticated request can trigger an unhandled exception in code paths that authenticate requests, causing a per-request denial of service without exposing tokens, sessions, or other data and without bypassing authentication. This issue is fixed in @auth/core 0.41.3 and next-auth 4.24.15 and 5.0.0-beta.32. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-20 Added CWE CWE-248 Added Reference https://github.com/nextauthjs/next-auth/commit/5bca2399a79ba8d116ca5179b4b1ebcd152e7f05 Added Reference https://github.com/nextauthjs/next-auth/commit/e707770f00c52b3479e43422b0200b059149ed53 Added Reference https://github.com/nextauthjs/next-auth/pull/13469 Added Reference https://github.com/nextauthjs/next-auth/releases/tag/%40auth%2Fcore%400.41.3 Added Reference https://github.com/nextauthjs/next-auth/releases/tag/next-auth%404.24.15 Added Reference https://github.com/nextauthjs/next-auth/releases/tag/next-auth%405.0.0-beta.32 Added Reference https://github.com/nextauthjs/next-auth/security/advisories/GHSA-xmf8-cvqr-rfgj