{"id":"CVE-2026-67991","title":"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","summary":"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 ca…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-1333"],"published":"2026-08-13","updated":"2026-09-08","sourceUpdated":"2026-09-08T19:42:20.313","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-67991","references":[{"url":"https://gist.github.com/Zykis1024/9f2d68fa3fd4e3a0ab83063bbe61a8e2","label":"cve@mitre.org"},{"url":"https://github.com/crmne/ruby_llm","label":"cve@mitre.org"},{"url":"https://github.com/crmne/ruby_llm/blob/fa6f279847d6d7027814539d9c0dfc3bbdfd2a83/lib/ruby_llm/utils.rb#L13","label":"cve@mitre.org"},{"url":"https://github.com/crmne/ruby_llm/commit/9d75b033d7d00c4e1baa9b0afb4828faa8bd6602","label":"cve@mitre.org"}],"tags":["nvd"],"epss":0.00508,"epssPercentile":0.40828,"ingestedAt":"2026-09-05T16:41:56.898Z","slug":"CVE-2026-67991","body":"## Overview\n\ncrmne/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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}