CVE-2026-66730 json
facil.io 0.6.0 - 0.7.6 Infinite Loop DoS via Multipart MIME Body Parser
published 2026-07-27 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-49359
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.8%
- EPSS 0.8% chance of exploitation in 30 days, percentile 56%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
0.78% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- tpaidakis.com https://tpaidakis.com/writeups/facilio-parser-dos/ referenced PoC, tagged "exploit" by a source, unverified
- github.com https://github.com/theopaid/Infinite-Loop-DoS-in-facil.io-MIME-Parser referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | 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 |
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| CNA | 4.0 | 8.7 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- boazsegev facil.io
Classification
- Weakness
-
- CWE-835 Loop with Unreachable Exit Condition
References
-
tpaidakis.com
/writeups/facilio-parser-dos/
technical-description, exploit
-
github.com
/theopaid/Infinite-Loop-DoS-in-facil.io-MIME-Parser
technical-description, exploit
-
vulncheck.com
/advisories/facil-io-infinite-loop-dos-via-multipart-mime-body-parser
third-party-advisory
Sources
- CVE List CVE-2026-66730
- NVD CVE-2026-66730
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