---
cve: "CVE-2026-67991"
severity: "HIGH"
cvss: 7.5
epss: "36%"
vendor: "n/a"
kev: false
exploited: false
published: "2026-08-13 14:17:11"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-05T16:41:33+02:00"
---

# CVE-2026-67991

> 7.5 HIGH · 🧪 PoC

## Beschreibung

crmne/ruby_llm at commit fa6f279847d6d7027814539d9c0dfc3bbdfd2a83 contains a polynomial-time regular expression denial-of-service condition in RubyLLM::Utils.underscore on Ruby 3.1.x. A very long crafted class, agent, or tool name can cause excessive CPU consumption and a denial of service.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Keine | good |
| A Verfügbarkeit | Keine | good |

## Referenzen

- <https://github.com/crmne/ruby_llm>
- <https://github.com/crmne/ruby_llm/blob/fa6f279847d6d7027814539d9c0dfc3bbdfd2a83/lib/ruby_llm/utils.rb#L13>
- <https://gist.github.com/Zykis1024/9f2d68fa3fd4e3a0ab83063bbe61a8e2>
- <https://github.com/crmne/ruby_llm/commit/9d75b033d7d00c4e1baa9b0afb4828faa8bd6602>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-67991) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_