facil.io 0.6.0 - 0.7.6 Integer Underflow DoS via Multipart MIME Body Parser
41Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 8.7epss 0.5%
from disclosure to weapon0 days
Published on NVDJul 27
1st PoCJul 24
exploitation probability
0.5%top 62% of all CVEs
observed exploitation
nono source reports it
2 public exploit(s)
facil.io 0.6.0 through 0.7.6 contains an integer underflow vulnerability in the multipart MIME body parser that allows unauthenticated remote attackers to crash the server process by sending a crafted Content-Disposition header with an empty field name. Attackers can trigger a uint32_t wraparound in http_mime_parser.h causing an out-of-bounds memory read past the name pointer, resulting in a bus fault that crashes the handling worker with a single POST request.
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
Affected products
boazsegev · facil.iopublic PoCs found — 2
githubgithub.com/theopaid/CVE-2026-66729-Out-of-Bounds-Read-in-facil.io-MIME-Parser-leads-to-Server-Crash★ 0cve_referencegithub.com/theopaid/Out-of-Bounds-Read-in-facil.io-MIME-Parser-leads-to-Server-Crashunverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.