7.5

CVE-2025-49826: vercel next.js HTTP Request/Response Smuggling

CVSS: 7.5v3.1HighAnalyzed
AliasesGHSA-67rr-84xm-4c7r
Published 03-07-2025Last modified 08-07-2025
Open JSON

Vulnerability summary

CVE-2025-49826 is a high (CVSS 7.5) HTTP Request/Response Smuggling vulnerability in vercel next.js. EPSS estimates a 1.13% chance of exploitation in the next 30 days, higher than 65.9% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
1.13%
0%100%
Low · +0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 03-07-2025
    PublishedVulnerability first disclosed.
  2. 08-07-2025
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

1.13%

Chance of exploitation in the next 30 days

Percentile

66%

Versus all other CVEs

30-day change

+0.04 pp

From 1.09% on 20-09-2026

20-09-202620-10-2026
EPSS score
1.13%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Npm1 product
  • next≥ 15.0.4-canary.51, < 15.1.8
Vercel1 product
  • next.js≥ 15.0.4-canary.51, < 15.1.8 | > 15.0.4, < 15.1.8 | 15.0.4:canary51 | 15.0.4:canary52

2 vendors · 2 products

References

7 links