{"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":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-1333"],"published":"2026-09-29","updated":"2026-10-01","sourceUpdated":"2026-10-01T16:17:47.723","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":0.00432,"epssPercentile":0.3724,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-01T15:21:55.298371Z"},"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":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":214379,"id":"CVE-2026-67987","ts":1790869808217,"field":"cvss","old":null,"new":"7.5"},{"seq":214378,"id":"CVE-2026-67987","ts":1790869808217,"field":"severity","old":"none","new":"high"}]}