Cross-Site Scripting (XSS) in @swc/html (CVE-2026-72925)
Summary
Cross-site scripting in @swc/html (CVE-2026-72925). Risk of unauthorized operations or information disclosure. Exploitable via script. Mitigation: upgrade to 1.15.47-nightly-20260729.1 or later.
Original description
The description as published by the source.
Impact
@swc/html minifies JSON contained in script elements such as
application/json and application/ld+json by parsing and serializing the
JSON value.
Before the patched versions, JSON serialization could convert escaped
less-than signs such as \u003C into literal < characters. If the JSON
contained an escaped `` sequence, the generated HTML could terminate
the containing script element early because HTML tokenization occurs before
the JSON is consumed.
Applications that minify HTML containing attacker-controlled JSON data could
therefore transform inert data into active markup. A crafted payload could
execute script in the origin of the generated page.
Patches
The issue is fixed in:
@swc/html1.15.47swc_html_minifier59.0.0
The minifier now re-escapes less-than signs after JSON serialization, preserving
the script element boundary.
Workarounds
Users who cannot upgrade can disable JSON minification with:
await minify(html, {
minifyJson: false,
});
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-72925 has been found in @swc/html.
Attackers can target a specific entry point like script over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.1/10.
What to do: upgrade @swc/html to 1.15.47-nightly-20260729.1 or later.
If unsure, ask your IT team or search "@swc/html CVE-2026-72925" on the vendor's site.
CVE-2026-72925 (@swc/html) — CWE-79 / CVSS v3 6.1
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: script / swc_html_minifier
Patched: 1.15.47-nightly-20260729.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in @swc/html. Attackers reach the vulnerable code path via script without authentication.
Check the vendor advisory for the affected versions of @swc/html. Attack surface: script / swc_html_minifier.
Severity: Medium (CVSS 6.1/10). Risk of unauthorized operations or information disclosure.
Update to 1.15.47-nightly-20260729.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '@swc/html' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r '@swc/html' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
@swc/htmlを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade @swc/html to 1.15.47-nightly-20260729.1ステージング環境で 1.15.47-nightly-20260729.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com