Vulnerability · Published Sep 29, 2026 · Assigned by mitre

CVE-2026-67987

High 7.5

In plain English

A high-severity regular-expression denial of service in the ruby-llm package (Ubuntu). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.4%top 62.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 many unterminated <think> tags can cause excessive CPU consumption in two consecutive regular expressions and delay chat-completion processing

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Ubuntu:26.10	ruby-llm	no fix listed	UBUNTU-CVE-2026-67987

Affected products (as reported)

Vendor	Product	Versions
n/a	n/a	n/a

Weakness: CWE-1333 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

In plain English

Official description

Affected packages & fixed versions

Affected products (as reported)

References