Resource exhaustion in Gtermars Javascript::minifier::xs
CVE-2026-56018
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.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (47.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 47.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Gtermars Javascript::minifier::xs — versions 0
Weakness classification (CWE)
References
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (issue-tracking)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (release-notes)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2026-56018?
- CVE-2026-56018 is a high-severity vulnerability in Gtermars Javascript::minifier::xs, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-06-29.
- How severe is CVE-2026-56018?
- High severity. CVSS v3 base score is 7.5 out of 10.