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Fencer Vulns
high 7.5

CVE-2026-56018 json

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

published 2026-06-29 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-40182

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

Summary

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.

Patch / fix

  • GTERMARS JavaScript::Minifier::XS 0.16
  • libjavascript-minifier-xs-perl Debian 14 0.16-1

debian advisories DEBIAN-CVE-2026-56018

  • perl-JavaScript-Minifier-XS openSUSE Tumbleweed 0.160.0-1.1

opensuse advisories openSUSE-SU-2026:11158-1

  • perl-javascript-minifier-xs Alpine 3.24 0.16-r0

alpine advisories ALPINE-CVE-2026-56018

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-56018 updated cvss 5.3

JavaScript::Minifier::XS: JavaScript::Minifier::XS: Denial of Service due to memory leak during minification.

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.61% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • GTERMARS JavaScript::Minifier::XS

Classification

Weakness
  • CWE-401 Missing Release of Memory after Effective Lifetime
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.