CVE-2026-45109
Published: 13 May 2026
Summary
CVE-2026-45109 is a high-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability in Vercel Next.Js. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 2.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-30085
Vulnerability details
Next.js is a React framework for building full-stack web applications. From 15.2.0 to before 15.5.18 and 16.2.6, it was found that the fix addressing CVE-2026-44575 did not apply to middleware.ts with Turbopack. This vulnerability is fixed in 15.5.18 and 16.2.6.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
CWE-288 auth bypass in public-facing Next.js middleware enables exploitation of exposed web apps (T1190).
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Authorizing remote access reduces the ability to bypass authentication via unauthorized alternate remote channels.
Users can identify logons via alternate paths or channels by reviewing the previous logon time.
Adaptive requirements can apply across access paths, reducing the ability to bypass authentication via alternate channels or paths.
Centralized IdPs close alternate authentication paths that enable bypass.
Enforces authentication for non-organizational users, making it harder to bypass via alternate paths or channels.
Requires authentication to occur exclusively over the isolated trusted path, directly preventing bypass via alternate or untrusted channels.