# CVE-2026-41146: Uncontrolled resource consumption and loop with unreachable exit condition in facil.io and downstream iodine ruby gem

> Attackers can cause a denial of service by sending malformed JSON that triggers an infinite loop in the facil.io and iodine parsers.

- **Severity:** High 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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Apr 2026
- **Updated:** 22 Apr 2026
- **Also known as:** GHSA-2x79-gwq3-vxxm

## What is CVE-2026-41146?

CVE-2026-41146 is a high-severity denial of service vulnerability in boazsegev facil.io, published on 22 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-835 (Loop with Unreachable Exit Condition), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-41146?

2 open source packages ship an affected version, including iodine.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `iodine` | RubyGems | All versions to 0.7.58 | None |
| `iodine` | RubyGems | All versions to 0.7.58 | None |

## How do I fix CVE-2026-41146?

No fix has been published for CVE-2026-41146 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-41146 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41146 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-41146 and fix it if it is affected.

What it is: CVE-2026-41146 is a high-severity denial of service vulnerability in boazsegev facil.io, published on 22 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41146 exists.

Affected packages and fixed versions:
- iodine (RubyGems): affected all versions up to 0.7.58; no fix listed
- iodine (RubyGems): affected all versions up to 0.7.58; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-41146/ (Markdown: https://insights.sbomify.com/CVE-2026-41146/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-41146
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41146
- OSV: https://osv.dev/vulnerability/CVE-2026-41146

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-41146/
Summaries are generated and may contain mistakes; the official description above is the record.