CVE-2026-56017
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk38th percentile — higher than 38% of all known CVEs
Summary
A vulnerability in JavaScript::Minifier::XS before version 0.16 for Perl causes a crash via NULL pointer dereference when the first meaningful token of the input is a slash. The issue occurs in the JsTokenizeString function during regexp versus division disambiguation.
Risk Assessment
An attacker can remotely crash the process by sending minimal input (e.g., a single slash) to a service that minifies untrusted JavaScript, leading to denial of service (DoS).
Recommendation
Immediately update JavaScript::Minifier::XS to version 0.16 or later. If an update is not possible, restrict access to minification services to trusted sources only.
Original NVD description (English source)
JavaScript::Minifier::XS versions before 0.16 for Perl crash with a NULL pointer dereference when the first meaningful token of the input is a slash. The regexp versus division disambiguator in JsTokenizeString (XS.xs) inspects the previous token's last byte to choose between a regexp literal and a division operator. When a slash is the first meaningful token, with the start of input or only whitespace and comments before it, there is no valid preceding token: the walk back over whitespace and comment nodes runs off the head of the node list to NULL, and the byte lookup reads through a NULL contents pointer at an underflowed length index. The following identifier check dereferences the same NULL pointer. The crash is reachable through the public minify() API, so input as small as a single slash byte crashes the calling process. A service that minifies untrusted or third-party JavaScript can be crashed by a remote request, causing denial of service.