CVE-2026-18998

MEDIUMPre-NVD 6.36.3—
EchelonGraph scoreHIGH confidence

Score 6.3 from GitHub Security Advisory (severity: LOW) published 2026-08-06. a secondary CVSS source baseline 6.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
6.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.3Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

A vulnerability was determined in cosmicstack-labs mercury-agent up to 1.1.12. Impacted is the function SubAgent.run of the file src/core/sub-agent.ts of the component delegate_task Tool. Executing a manipulation can lead to improper authorization. It is possible to launch the attack remotely. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.

CVSS v3
6.3
EG Score
6.3(high)
EG Risk
44(Track)
EG Risk 44/100SSVC: Track

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
Severity63% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
11%
KEV
Not listed

Published

August 6, 2026

Last Modified

August 12, 2026

Advisory Details (2)

Auto-updated Aug 6, 2026
No patch confirmed yet.
generic

GitHub - cosmicstack-labs/mercury-agent: Soul-driven AI agent with permission-hardened tools, token budgets, and multi-channel access. Runs 24/7 from CLI or Telegram. · GitHub

https://github.com/cosmicstack-labs/mercury-agent/
generic

[Security] Restricted Mercury sub-agents can enumerate and halt sibling agents despite `allowedTools` constraints · Issue #74 · cosmicstack-labs/mercury-agent · GitHub

https://github.com/cosmicstack-labs/mercury-agent/issues/74

Vendor Advisories for CVE-2026-18998(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 18× in last 7d / 47× 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. 2026-08-20 22:55 UTCEPSS rescore
  2. 2026-08-20 10:44 UTCEG score recompute
  3. 2026-08-20 10:44 UTCGHSA enrichment
  4. 2026-08-19 17:03 UTCEPSS rescore
  5. 2026-08-19 08:47 UTCEG score recompute
  6. 2026-08-19 08:47 UTCGHSA enrichment
  7. 2026-08-18 13:48 UTCEPSS rescore
  8. 2026-08-18 06:50 UTCEG score recompute
  9. 2026-08-18 06:50 UTCGHSA enrichment
  10. 2026-08-17 13:47 UTCEPSS rescore
  11. 2026-08-17 04:53 UTCEG score recompute
  12. 2026-08-17 04:53 UTCGHSA enrichment
  13. 2026-08-16 14:56 UTCEPSS rescore
  14. 2026-08-16 02:57 UTCEG score recompute
  15. 2026-08-16 02:57 UTCGHSA enrichment
  16. 2026-08-16 02:14 UTCEPSS rescore
  17. 2026-08-15 01:30 UTCEPSS rescore
  18. 2026-08-15 01:01 UTCGHSA enrichment
  19. 2026-08-13 23:05 UTCEG score recompute
  20. 2026-08-13 23:05 UTCGHSA enrichment
  21. 2026-08-13 22:00 UTCEPSS rescore
  22. 2026-08-12 21:07 UTCEG score recompute
  23. 2026-08-12 21:07 UTCGHSA enrichment
  24. 2026-08-12 13:50 UTCEPSS rescore
  25. 2026-08-12 08:05 UTCEG score recompute
Show 22 more
  1. 2026-08-12 08:05 UTCGHSA enrichment
  2. 2026-08-11 13:42 UTCEPSS rescore
  3. 2026-08-11 06:08 UTCEG score recompute
  4. 2026-08-11 06:08 UTCGHSA enrichment
  5. 2026-08-11 00:00 UTCEPSS rescore
  6. 2026-08-10 04:12 UTCEG score recompute
  7. 2026-08-10 04:12 UTCGHSA enrichment
  8. 2026-08-09 13:46 UTCEPSS rescore
  9. 2026-08-09 02:16 UTCEG score recompute
  10. 2026-08-09 02:16 UTCGHSA enrichment
  11. 2026-08-08 16:37 UTCEPSS rescore
  12. 2026-08-08 00:20 UTCEG score recompute
  13. 2026-08-08 00:20 UTCGHSA enrichment
  14. 2026-08-06 22:24 UTCEG score recompute
  15. 2026-08-06 22:24 UTCGHSA enrichment
  16. 2026-08-06 22:18 UTCNVD updateCVSS v4 → 2.1
  17. 2026-08-06 22:15 UTCMITRE cvelistV5CVSS v4 → 5.3
  18. 2026-08-06 13:46 UTCEPSS rescore
  19. 2026-08-06 06:17 UTCEG score recompute
  20. 2026-08-06 06:17 UTCNVD updateCVSS v4 → 2.1
  21. 2026-08-06 05:30 UTCEG score recompute
  22. 2026-08-06 05:30 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18998?
CVE-2026-18998 is a medium vulnerability published on August 6, 2026. A vulnerability was determined in cosmicstack-labs mercury-agent up to 1.1.12. Impacted is the function SubAgent.run of the file src/core/sub-agent.ts of the component delegate_task Tool. Executing a manipulation can lead to improper authorization. It is possible to launch the attack remotely. The…
When was CVE-2026-18998 disclosed?
CVE-2026-18998 was first published in the National Vulnerability Database on August 6, 2026, with the most recent update on August 12, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18998 actively exploited?
CVE-2026-18998 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 88.6% of all scored CVEs.
What is the CVSS score of CVE-2026-18998?
CVE-2026-18998 has a CVSS v3 base score of 6.3 (NVD).
How do I remediate CVE-2026-18998?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18998, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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