CVE-2025-49826 | Next.js DoS vulnerability via cache poisoning

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.

Published: 2025-07-03 Last update: 2025-09-10 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-49826 is rated Moderate Risk (43.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.17%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-49826

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-29 0.05% 0.17% +0.12%
2 2026-03-29 0.05% 0.05% -0.00%
3 2026-03-08 — 0.05% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-49826

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-49826

GitHub Security Advisory for CVE-2025-49826

GHSA-67rr-84xm-4c7r · Severity: high · Ecosystem: npm — Next.JS vulnerability can lead to DoS via cache poisoning

OS Trackers for CVE-2025-49826

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2025-49826

Affected software / configurations for CVE-2025-49826

Vendor Product Version Raw CPE
vercel next.js > 15.0.4, < 15.1.8 cpe:2.3:a:vercel:next.js:*:*:*:*:*:node.js:*:*
vercel next.js 15.0.4 cpe:2.3:a:vercel:next.js:15.0.4:canary51:*:*:*:node.js:*:*
vercel next.js 15.0.4 cpe:2.3:a:vercel:next.js:15.0.4:canary52:*:*:*:node.js:*:*

References for CVE-2025-49826

cvelogic Threat Intelligence