Vulnerability Report

CVE-2026-44581

Title: Next.js App Router CSP Nonce Stored Cross-site Scripting

XSS

Proof Of Concept

No public PoC currently indexed for CVE-2026-44581.

CWE Category CWE-79

Published Date May 13, 2026

Modified Date May 14, 2026

Exploit Status Not Found

Score 4.7 CVSS v3.1

Exploit Probability (EPSS)

0.22%

Vulnerability Summary

CVE-2026-44581: Next.js is a React framework for building full-stack web applications. From 13.4.0 to before 15.5.16 and 16.2.5, App Router applications that rely on CSP nonces can be vulnerable to stored cross-site scripting when deployed behind shared caches. In affected versions, malformed nonce values derived from request headers could be reflected into rendered HTML in an unsafe way, allowing an attacker to poison cached responses and cause script execution for later visitors. This vulnerability is fixed in 15.5.16 and 16.2.5.

Impacted Vendors

vercel 1

kanopi 1

Reference Links

https://github.com/vercel/next.js/security/advisories/GHSA-ffhc-5mcf-pf4q

CVSS v3.1

Source Entity [email protected]

Severity MEDIUM

4.7

Attack Vector

NETWORK

Complexity

HIGH

Privileges

N/A

Interaction

REQUIRED

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

CHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-44581 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

May 14, 2026 MODIFIED

Vulnerability data updated via NVD.

May 13, 2026 MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK

Complexity HIGH

Privileges N/A

Interaction REQUIRED

CVSS Vector String


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

Affected Stack

No specific products linked.