CVE-2026-67991 Denial of service in n/a
An attacker can cause denial of service via excessive CPU consumption in the RubyLLM library by submitting crafted long names.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-67991?
CVE-2026-67991 is a high-severity denial of service vulnerability in n/a, published on 13 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-1333
Which versions are affected by CVE-2026-67991?
How do I fix CVE-2026-67991?
No fix has been published for CVE-2026-67991 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-67991 being exploited?
There is no known exploitation of CVE-2026-67991 in the wild and no public exploit code.
Sources
Also known as GHSA-42r3-x6vx-x49x.