CVE-2025-71319
CVE-2025-71319 is a CWE-835 vulnerability in image-size. O3 Security confirms whether CVE-2025-71319 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
image-size 2.0.2 Denial of Service via Infinite Loop in JXL/HEIF Parser
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
image-sizenpmDescription
image-size through 2.0.2 contains a denial of service vulnerability that allows remote attackers to permanently block the Node.js event loop by supplying a specially crafted image buffer with a zero-valued size field in a recognized box-type. Attackers can trigger an infinite loop in the JXL or HEIF image parsers by providing a crafted image containing a box with a size of zero, causing the offset to never advance and permanently hanging the application.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | image-size | ≥ 1.1.0&&< 1.2.1 | 1.2.1 |
| 📦npm | image-size | ≥ 2.0.0&&< 2.0.2 | 2.0.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for image-size. 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 image-size to 1.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-71319 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-2025-71319 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-2025-71319. 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-2025-71319 in your dependencies?
O3 detects CVE-2025-71319 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.