CVE-2025-49826

Next.js DoS vulnerability via cache poisoning

HIGH
7.5
CVSS Score
Published: July 3, 2025 at 09:03 PM UTC
Updated: June 17, 2026 at 09:31 AM UTC
1 product affected across 1 vendorNext.js

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Severity
HIGH7.5
Exploit prediction
EPSS 1%
SSVC
No known exploit

Description

Next.js is a React framework for building full-stack web applications. From versions 15.0.4-canary.51 to before 15.1.8, a cache poisoning bug leading to a Denial of Service (DoS) condition was found in Next.js. This issue does not impact customers hosted on Vercel. Under certain conditions, this issue may allow a HTTP 204 response to be cached for static pages, leading to the 204 response being served to all users attempting to access the page. This issue has been addressed in version 15.1.8.

Affected

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

v < 15.1.815.0.4 < v < 15.1.815.0.4 canary5115.0.4 canary52
Affected range stops below 15.1.8, 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:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

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

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-444

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