CVE-2026-41146

HIGH EPSS 21.1%
Published Apr 22, 20262mo ago · Modified Jun 17, 20262w ago
8.7 CVSS 4.0
High
Find Similar
Published Apr 22, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

Description

facil.io is a C micro-framework for web applications. Prior to commit 5128747363055201d3ecf0e29bf0a961703c9fa0, `fio_json_parse` can enter an infinite loop when it encounters a nested JSON value starting with `i` or `I`. The process spins in user space and pegs one CPU core at ~100% instead of returning a parse error. Because `iodine` vendors the same parser code, the issue also affects `iodine` when it parses attacker-controlled JSON. The smallest reproducer I found is `[i`. The quoted-value form that originally exposed the issue, `[""i`, reaches the same bug because the parser tolerates missing commas and then treats the trailing `i` as the start of another value. Commit 5128747363055201d3ecf0e29bf0a961703c9fa0 fixes the issue.

CVSS Details

Base Score
8.7
Exploitability
—
Impact
—
Vector string
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
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
21.1% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 2

CWE-400 Uncontrolled Resource Consumption Resource Mgmt
CWE-835

References 2

  • github.com https://github.com/boazsegev/facil.io/commit/5128747363055201d3ecf0e29bf0a961703c9fa0
  • github.com https://github.com/boazsegev/facil.io/security/advisories/GHSA-2x79-gwq3-vxxm

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.