Description
SWC is a TypeScript / JavaScript compiler written in Rust. Prior to @swc/html 1.15.47-nightly-20260729.1 and swc_html_minifier 59.0.0, the minifyJson processing in crates/swc_html_minifier/src/lib.rs parsed and serialized attacker-controlled JSON in application/json and application/ld+json script elements without the escape_json_for_html_script behavior to re-escape less-than signs, allowing a closing script sequence to terminate the element early and execute script in the generated page's origin. This issue is fixed in @swc/html 1.15.47-nightly-20260729.1 and swc_html_minifier 59.0.0.
References5
Metrics
- CVSS 3.1
-
6.1
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 28 · as of 12 November 2026
- CWE
- CWE-79CWE-116
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.