CVE-2026-67987

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-29. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 5 sources updated this week
7.5EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 7.5Exploit: None knownExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

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 tags can cause excessive CPU consumption in two consecutive regular expressions and delay chat-completion processing

CVSS v3
7.5
EG Score
7.5HIGHhigh confidence
EG Risk
49
EG Risk 49/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release.
EPSS PROB
0.4%
EPSS %ILE
35th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 29, 2026

Last Modified

October 1, 2026

Advisory Details (3)

Auto-updated Oct 1, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
github_commit

commit 5e88411f1717 (crmne/ruby_llm)

Fix landed in crmne/ruby_llm commit 5e88411f1717 — awaiting tagged release

https://github.com/crmne/ruby_llm/commit/5e88411f171721b381853fa77d254e266dcf6ad8
generic

ruby_llm/lib/ruby_llm/protocols/chat_completions/chat.rb at fa6f279847d6d7027814539d9c0dfc3bbdfd2a83 · crmne/ruby_llm · GitHub

https://github.com/crmne/ruby_llm/blob/fa6f279847d6d7027814539d9c0dfc3bbdfd2a83/lib/ruby_llm/protocols/chat_completions/chat.rb#L355-L356
generic

GitHub - crmne/ruby_llm: The Ruby-native AI framework. Chats, agents, tools, images, audio, and video through one consistent API, in plain Ruby or Rails. · GitHub

https://github.com/crmne/ruby_llm

Vendor Advisories for CVE-2026-67987(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 22× in last 7d / 22× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-04 10:22 UTCGHSA enrichment
  2. 2026-10-03 23:25 UTCEG score recompute
  3. 2026-10-03 23:25 UTCGHSA enrichment
  4. 2026-10-03 14:26 UTCEPSS rescore
  5. 2026-10-03 12:28 UTCGHSA enrichment
  6. 2026-10-03 01:31 UTCEG score recompute
  7. 2026-10-03 01:31 UTCGHSA enrichment
  8. 2026-10-02 17:56 UTCEPSS rescore
  9. 2026-10-02 14:35 UTCGHSA enrichment
  10. 2026-10-02 03:36 UTCEG score recompute
  11. 2026-10-02 03:36 UTCGHSA enrichment
  12. 2026-10-01 19:50 UTCEPSS rescore
  13. 2026-10-01 16:40 UTCGHSA enrichment
  14. 2026-10-01 15:26 UTCEG score recompute▲ 7.50
  15. 2026-10-01 15:26 UTCGHSA enrichment
  16. 2026-10-01 15:25 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  17. 2026-09-30 17:46 UTCEG score recompute
  18. 2026-09-30 17:46 UTCGHSA enrichment
  19. 2026-09-30 15:03 UTCEPSS rescore
  20. 2026-09-29 20:22 UTCNVD update
  21. 2026-09-29 20:00 UTCEG score recompute
  22. 2026-09-29 19:58 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-67987?
CVE-2026-67987 is a high vulnerability published on September 29, 2026. 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…
When was CVE-2026-67987 disclosed?
CVE-2026-67987 was first published on September 29, 2026, with the most recent update on October 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-67987 actively exploited?
CVE-2026-67987 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (35th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-67987?
CVE-2026-67987 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-67987?
An upstream fix for CVE-2026-67987 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-67987 are linked in the Vendor Advisories panel on this page.

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