CVE-2026-66730Public exploitNetwork attack vector

Unauthenticated service hang via stalled multipart parser

Published Jul 27, 2026 · Updated Jul 27, 2026

Denial of service in facil.io 0.6.0 through 0.7.6 allows remote attackers to hang server workers via a partial multipart closing boundary. The http_parse_body loop re-invokes http_mime_parse on the same buffer when the parser consumes zero bytes without setting done or error. One unauthenticated POST can freeze one worker at full CPU; requests matching the worker count hang the service until manual restart.

CVSS severity7.5
High
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in facil.io 0.6.0 through 0.7.6 allows remote attackers to hang server workers via a partial multipart closing boundary. The http_parse_body loop re-invokes http_mime_parse on the same buffer when the parser consumes zero bytes without setting done or error. One unauthenticated POST can freeze one worker at full CPU; requests matching the worker count hang the service until manual restart.

The record

CVE
CVE-2026-66730
Published
Jul 27, 2026
Updated
Jul 27, 2026
Vendor
Boaz Segev
Product
facil.io
Classifications
CWE-835, CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.6.0 <=0.7.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Boaz Segev · facil.ioversion=0.6.0 <=0.7.6

Published CVSS scores

7.5CVE-2026-66730 security advisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition
CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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