{"id":"CVE-2026-67987","title":"crmne/ruby_llm at commit fa6f279847d6d7027814539d9c0dfc3bbdfd2a83 contains polynomial-time regular expression denial-of-service conditions in think-tag response parsing on Ruby 3.1.x","summary":"crmne/ruby_llm at commit fa6f279847d6d7027814539d9c0dfc3bbdfd2a83 contains polynomial-time regular expression denial-of-service conditions in think-tag response parsing on Ruby 3.1.x. A malicious or anomalous model response containing ma…","severity":"none","published":"2026-09-29","updated":"2026-09-30","sourceUpdated":"2026-09-30T17:32:07.107","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-67987","references":[{"url":"https://github.com/crmne/ruby_llm","label":"cve@mitre.org"},{"url":"https://github.com/crmne/ruby_llm/blob/fa6f279847d6d7027814539d9c0dfc3bbdfd2a83/lib/ruby_llm/protocols/chat_completions/chat.rb#L355-L356","label":"cve@mitre.org"},{"url":"https://github.com/crmne/ruby_llm/commit/5e88411f171721b381853fa77d254e266dcf6ad8","label":"cve@mitre.org"}],"tags":["nvd","cve.org"],"epss":0.00166,"epssPercentile":0.05235,"ingestedAt":"2026-09-29T20:46:06.446Z","slug":"CVE-2026-67987","body":"## Overview\n\ncrmne/ruby_llm at commit fa6f279847d6d7027814539d9c0dfc3bbdfd2a83 contains polynomial-time regular expression denial-of-service conditions in think-tag response parsing on Ruby 3.1.x. A malicious or anomalous model response containing many unterminated <think> tags can cause excessive CPU consumption in two consecutive regular expressions and delay chat-completion processing\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}