CVE-2026-56018 Details
Description
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.
A memory leak vulnerability has been identified in JavaScript::Minifier::XS versions prior to 0.16 for Perl. The issue arises in the minify() function, where the cleanup process only frees certain structures but fails to release the memory allocated for each token's contents. This oversight leads to unbounded memory growth with each minification call. In long-lived processes that repeatedly minify JavaScript, such as asset pipelines or server-side minification endpoints, this memory leak can exhaust available system RAM, causing the process to be terminated and resulting in a denial-of-service condition.
Users can upgrade to JavaScript::Minifier::XS version 0.16 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jun 29, 2026CISA-ADP
Assessed Jun 29, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/bleargh45/JavaScript-Minifier-XS/issues/10 | CPANSec | ExploitIssue TrackingTechnical DescriptionVendor |
| https://metacpan.org/release/GTERMARS/JavaScript-Minifier-XS-0.16/changes | CPANSec | Release NotesVendor |
| http://www.openwall.com/lists/oss-security/2026/06/29/17 | CVE |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-400 | Uncontrolled Resource Consumption | CPANSec |
| CWE-401 | Missing Release of Memory after Effective Lifetime | CPANSec |
Affected Products
| Product | Versions |
|---|---|
| JavaScript::Minifier::XS | < 0.16 |
CPE
Remediation
| |
Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 29, 2026 | CVE Modified | CVE |
| Jun 29, 2026 | CVE Modified | CISA-ADP |
| Jun 29, 2026 | New CVE Received | CPANSec |