SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-67731

Prior to 1.2, the Express server used express.json() without a size limit, which could allow attackers to send extremely large request bodies.

HIGH 8.7EPSS 0.40%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.40%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Servify Express is a Node.js package to start an Express server and log the port it's running on. Prior to 1.2, the Express server used express.json() without a size limit, which could allow attackers to send extremely large request bodies. This can cause excessive memory usage, degraded performance, or process crashes, resulting in a Denial of Service (DoS). Any application using the JSON parser without limits and exposed to untrusted clients is affected. The issue is not a flaw in Express itself, but in configuration. This issue is fixed in version 1.2. To work around, consider adding a limit option to the JSON parser, rate limiting at the application or reverse-proxy level, rejecting unusually large requests before parsing, or using a reverse proxy (such as NGINX) to enforce maximum request body sizes.

CVSS 4.0
8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.40% probability · 34th percentile
CISA KEV
Not listed
Weakness
CWE-400
Affected
servify-express.js/servify express
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.