CVE-2026-56018CWE-400CWE-401

JavaScript::Minifier::XS versions before 0.16 for Perl leak memory on every call to minify(), allowing unbounded memory growth

High · published June 29, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
48.5
In the wild
Unconfirmed
What it is

JavaScript::Minifier::XS versions before 0.16 for Perl leak memory on every call to minify(), allowing unbounded memory growth.

In JsMinify (XS.xs) the cleanup frees only the NodeSet structures and never the per-token contents buffers allocated in JsSetNodeContents; JsDiscardNode unlinks nodes without freeing their contents. Each token's contents buffer is therefore leaked on every call, and the two early returns taken when the node list is empty leak the whole NodeSet.

A long-lived process that minifies repeatedly, such as an asset pipeline or a server-side minifier endpoint, grows in memory without bound until it exhausts available memory and is killed, causing denial of service.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00609 · 48.5th percentile
Weaknesses
CWE-400 · Uncontrolled Resource Consumption; CWE-401 · Missing Release of Memory after Effective Lifetime
Published
2026-06-29T19:38Z
EPSS history
Timeline
  • 29 JUN 19:38Z
    JavaScript::Minifier::XS versions before 0.16 for Perl leak memory on every call to minify(), allowing unbounded memory growth
    cvelistv5