SWC HTML minifier may allow script element breakout when minifying embedded JSON
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.1epss 0.2%
exploitation probability
0.2%top 91% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
References
https://github.com/swc-project/swc/commit/e1877b44bdac8abc9fd51e984d584f40f6999832https://github.com/swc-project/swc/pull/12080https://github.com/swc-project/swc/releases/tag/v1.15.47https://github.com/swc-project/swc/releases/tag/v1.15.47-nightly-20260729.1https://github.com/swc-project/swc/security/advisories/GHSA-5qr2-v392-m9g8