# CVE-2026-72925: SWC HTML minifier may allow script element breakout when minifying embedded JSON

> An attacker can execute arbitrary JavaScript in the victim's browser by injecting a closing script tag into JSON data processed by the SWC HTML minifier.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 11 Aug 2026
- **Updated:** 11 Aug 2026
- **Also known as:** GHSA-5qr2-v392-m9g8

## What is CVE-2026-72925?

CVE-2026-72925 is a medium-severity cross-site scripting vulnerability in @swc html, published on 11 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-116 (Improper Encoding or Escaping of Output)

## Which versions are affected by CVE-2026-72925?

4 open source packages ship an affected version, including @swc/html and swc_html_minifier.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@swc/html` | npm | All versions | 1.15.47-nightly-20260729.1 |
| `@swc/html` | npm | All versions | 1.15.47-nightly-20260729.1 |
| `swc_html_minifier` | crates.io | All versions | 59.0.0 |
| `swc_html_minifier` | crates.io | All versions | 59.0.0 |

## How do I fix CVE-2026-72925?

Upgrade @swc/html to 1.15.47-nightly-20260729.1 or later.

## Is CVE-2026-72925 being exploited?

There is no known exploitation of CVE-2026-72925 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72925 and fix it if it is affected.

What it is: CVE-2026-72925 is a medium-severity cross-site scripting vulnerability in @swc html, published on 11 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-72925 in the wild and no public exploit code.

Affected packages and fixed versions:
- @swc/html (npm): affected all versions; fixed in 1.15.47-nightly-20260729.1
- @swc/html (npm): affected all versions; fixed in 1.15.47-nightly-20260729.1
- swc_html_minifier (crates.io): affected all versions; fixed in 59.0.0
- swc_html_minifier (crates.io): affected all versions; fixed in 59.0.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-72925/ (Markdown: https://insights.sbomify.com/CVE-2026-72925/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72925
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72925
- OSV: https://osv.dev/vulnerability/CVE-2026-72925

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72925/
Summaries are generated and may contain mistakes; the official description above is the record.