Single-core denial of service via stalled JSON cursor
Published Apr 22, 2026 · Updated Apr 22, 2026
An infinite-loop denial of service in facil.io and iodine allows remote attackers to consume one CPU core through crafted JSON input. In fio_json_parse, a nested malformed inf-prefix token leaves integer and floating-point conversion at the same input position, but the parser accepts the unchanged cursor and repeats indefinitely. Reachability requires an application to pass attacker-controlled JSON to the vendored parser; the affected process spins in user space rather than returning a parse error.
Summary
What happened
An infinite-loop denial of service in facil.io and iodine allows remote attackers to consume one CPU core through crafted JSON input. In fio_json_parse, a nested malformed inf-prefix token leaves integer and floating-point conversion at the same input position, but the parser accepts the unchanged cursor and repeats indefinitely. Reachability requires an application to pass attacker-controlled JSON to the vendored parser; the affected process spins in user space rather than returning a parse error.
The record
- CVE
- CVE-2026-41146
- Published
- Apr 22, 2026
- Updated
- Apr 22, 2026
- Vendor
- Boaz Segev
- Product
- iodine
- Classifications
- CWE-400, CWE-835, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 22, 2026CVE publishedPublication date reported by the CVE source.
- Apr 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.7.59
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- GHSA nested i-token JSON reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo