← Vulnerability feed

Vulnerability record · CVE-2026-73418 · published 12 August 2026

CVE-2026-73418: Improper input validation vulnerability

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.

7.5 CVSS 3.1 High EPSS 0.88% · top 42.6% CWE-20 · Improper input validationCWE-248 · CWE-248 Awaiting Analysis
7.5CVSS 3.1 base score
0.88%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
7References
9 Sep 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

LinkTags
https://github.com/nextauthjs/next-auth/commit/5bca2399a79ba8d116ca5179b4b1ebcd152e7f05
https://github.com/nextauthjs/next-auth/commit/e707770f00c52b3479e43422b0200b059149ed53
https://github.com/nextauthjs/next-auth/pull/13469
https://github.com/nextauthjs/next-auth/releases/tag/%40auth%2Fcore%400.41.3
https://github.com/nextauthjs/next-auth/releases/tag/next-auth%404.24.15
https://github.com/nextauthjs/next-auth/releases/tag/next-auth%405.0.0-beta.32
https://github.com/nextauthjs/next-auth/security/advisories/GHSA-xmf8-cvqr-rfgj

Track CVE-2026-73418 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.5CVE-2026-88771Citrix netscaler application delivery controller improper input validation vulnerabilityImproper input validation vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway. This issue affects ADC: before 14.1-73.37, before 13.1-…KEV9.5CVE-2026-93952Arista velocloud orchestrator improper input validation vulnerabilityVeloCloud Orchestrator (VCO) on-prem has a security issue where this issue may allow a remote attacker to access privileged internal functionality an…KEVEPSS 1.1%8.8CVE-2019-1068Microsoft SQL Server improper input validation remote code executionMicrosoft SQL Server mishandles processing of internal functions, allowing an authenticated remote attacker to execute code on the database server. T…KEVEPSS 58%analysed5.9CVE-2025-68686FortiOS symbolic link patch bypass exposes sensitive informationFortiOS contains an information exposure flaw (CWE-200) that lets a remote unauthenticated attacker bypass the patch for the symbolic link persistenc…KEVEPSS 30%analysed9.3CVE-2026-12569PTC Windchill PDMlink and FlexPLM deserialization RCEPTC Windchill PDMlink and FlexPLM contain a deserialization of untrusted data flaw (also classified as improper input validation) that allows remote …KEVEPSS 46%analysed10.0CVE-2026-34910Ubiquiti UniFi OS input validation flaw allows command injectionUniFi OS devices contain an improper input validation vulnerability (CWE-20) that lets a network-reachable attacker inject and execute commands. It a…KEVEPSS 46%analysed7.2CVE-2026-6973Ivanti EPMM improper input validation enables remote code executionIvanti Endpoint Manager Mobile (EPMM) before versions 12.6.1.1, 12.7.0.1, and 12.8.0.1 contains an improper input validation flaw (CWE-20) that lets …KEVEPSS 2.5%analysed7.5CVE-2026-20133Cisco Catalyst SD-WAN Manager insufficient file system restrictions expose dataCisco Catalyst SD-WAN Software has insufficient file system restrictions that let an attacker read sensitive files on the underlying operating system…KEVEPSS 32%analysed

Source: NIST National Vulnerability Database (record CVE-2026-73418), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.