Uncontrolled resource consumption and loop with unreachable exit condition in facil.io and downstream iodine ruby gem

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 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 · score source

EPSS

• CVE-2026-41146: 0.36% estimated exploitation activity in the next 30 days; percentile 30.36 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary fiojsonparse 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 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. Details The vulnerable logic is in lib/facil/fiobj/fiojsonparser.h around the numeral handling block (0.7.5 / 0.7.6: lines 434-468; master: lines 434-468 in the current tree as tested). This parser is reached from real library entry points, not just the header in isolation: - facil.io: lib/facil/fiobj/fiobjjson.c:377-387 (fiobjjson2obj) and 402-411 (fiobjhashupdatejson) - iodine: ext/iodine/iodinejson.c:161-177 (iodinejsonconvert) - iodine:…

Published by the source

14 Apr 2026, 23:41 UTC

Last modified by the source

8 Jun 2026, 23:17 UTC

Source last checked

26 Oct 2026, 15:52 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2x79-gwq3-vxxm

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# Patch Next advisory brief: CVE-2026-41146

Advisory: Uncontrolled resource consumption and loop with unreachable exit condition in facil.io and downstream iodine ruby gem
IDs: CVE-2026-41146, GHSA-2x79-gwq3-vxxm
Record: https://patchnext.com/advisories/cve-2026-41146 (revision 1, source checked 26 Oct 2026, 15:52 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems iodine: affected <= 0.7.58

## Suggested inspection (read-only)
- RubyGems iodine: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on iodine.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2x79-gwq3-vxxm (GitHub-reviewed advisory GHSA-2x79-gwq3-vxxm lists affected ranges: RubyGems iodine >=0 <=0.7.58)

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