CVE-2026-29074
HIGHCVE-2026-29074 is a high-severity (CVSS 7.5) CWE-776 vulnerability in svgo. O3 Security confirms whether CVE-2026-29074 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
SVGO: DoS through entity expansion in DOCTYPE (Billion Laughs)
Blast Radius
svgo📦svgo📦svgoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
SVGO, short for SVG Optimizer, is a Node.js library and command-line application for optimizing SVG files. From version 2.1.0 to before version 2.8.1, from version 3.0.0 to before version 3.3.3, and before version 4.0.1, SVGO accepts XML with custom entities, without guards against entity expansion or recursion. This can result in a small XML file (811 bytes) stalling the application and even crashing the Node.js process with JavaScript heap out of memory. This issue has been patched in versions 2.8.1, 3.3.3, and 4.0.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | svgo | ≥ 2.1.0&&< 2.8.1 | 2.8.1 |
| 📦npm | svgo | ≥ 3.0.0&&< 3.3.3 | 3.3.3 |
| 📦npm | svgo | ≥ 4.0.0&&< 4.0.1 | 4.0.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for svgo. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update svgo to 2.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-29074 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-29074 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-29074. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-29074 in your dependencies?
O3 detects CVE-2026-29074 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.