CVE-2026-44580

Next.js: Cross-site scripting in beforeInteractive scripts with untrusted input

MEDIUM
6.1
CVSS Score
Published: May 13, 2026 at 05:06 PM UTC
Updated: October 26, 2026 at 02:10 PM UTC
1 product affected across 1 vendorNext.js

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Severity
MEDIUM6.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

Next.js is a React framework for building full-stack web applications. From 13.0.0 to before 15.5.16 and 16.2.5, applications that use beforeInteractive scripts together with untrusted content can be vulnerable to cross-site scripting. In affected versions, serialized script content was not escaped safely before being embedded into the document, which could allow attacker-controlled input to break out of the intended script context and execute arbitrary JavaScript in a visitor's browser. This vulnerability is fixed in 15.5.16 and 16.2.5.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

13.0.0 ≤ v < 15.5.1616.0.0 ≤ v < 16.2.5
Affected range stops below 15.5.16, so it looks safe — our inference, not a vendor statement
Affected range stops below 16.2.5, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

x_refsource_CONFIRMMitigationVendor Advisory
Source: cverecord
https://github.com/vercel/next.js/security/advisories/GHSA-gx5p-jg67-6x7h

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.1MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-79

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