CVE-2026-18991

HIGHPre-NVD 7.37.3—
EchelonGraph scoreHIGH confidence

Score 7.3 from GitHub Security Advisory published 2026-08-06. a secondary CVSS source baseline 7.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
7.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.3Exploit: Elevated riskExposed: 0

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

A security vulnerability has been detected in nanocoai NanoClaw up to 2.0.64. This affects an unknown part of the file container/agent-runner/src/mcp-tools/core.ts of the component send_file. Such manipulation leads to path traversal. The attack can be executed remotely. The exploit has been disclosed publicly and may be used. The project was informed of the problem early through an issue report but has not responded yet.

CVSS v3
7.3
EG Score
7.3(high)
EG Risk
64(Attend)
EG Risk 64/100SSVC: Attend

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
Severity73% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
40%
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 - nanocoai/nanoclaw: A lightweight alternative to OpenClaw that runs in containers for security. Connects to WhatsApp, Telegram, Slack, Discord, Gmail and other messaging apps,, has memory, scheduled jobs, and runs directly on Anthropic's Agents SDK · GitHub

https://github.com/nanocoai/nanoclaw/
generic

[Security] Arbitrary local file exfiltration via `send_file` absolute path handling · Issue #2760 · nanocoai/nanoclaw · GitHub

https://github.com/nanocoai/nanoclaw/issues/2760

Vendor Advisories for CVE-2026-18991(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 28× in last 7d / 66× 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. 2026-08-21 09:24 UTCEG score recompute
  2. 2026-08-21 09:24 UTCGHSA enrichment
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-20 21:25 UTCGHSA enrichment
  5. 2026-08-20 09:26 UTCGHSA enrichment
  6. 2026-08-19 21:27 UTCEG score recompute
  7. 2026-08-19 21:27 UTCGHSA enrichment
  8. 2026-08-19 17:03 UTCEPSS rescore
  9. 2026-08-19 09:04 UTCGHSA enrichment
  10. 2026-08-18 21:01 UTCEG score recompute
  11. 2026-08-18 21:01 UTCGHSA enrichment
  12. 2026-08-18 13:48 UTCEPSS rescore
  13. 2026-08-18 09:01 UTCGHSA enrichment
  14. 2026-08-17 21:00 UTCEG score recompute
  15. 2026-08-17 21:00 UTCGHSA enrichment
  16. 2026-08-17 13:47 UTCEPSS rescore
  17. 2026-08-17 09:00 UTCGHSA enrichment
  18. 2026-08-16 21:01 UTCEG score recompute
  19. 2026-08-16 21:01 UTCGHSA enrichment
  20. 2026-08-16 14:56 UTCEPSS rescore
  21. 2026-08-16 09:01 UTCEG score recompute
  22. 2026-08-16 09:01 UTCGHSA enrichment
  23. 2026-08-16 02:14 UTCEPSS rescore
  24. 2026-08-15 21:02 UTCGHSA enrichment
  25. 2026-08-15 09:03 UTCEG score recompute
Show 41 more
  1. 2026-08-15 09:03 UTCGHSA enrichment
  2. 2026-08-15 01:30 UTCEPSS rescore
  3. 2026-08-14 21:03 UTCGHSA enrichment
  4. 2026-08-14 09:04 UTCEG score recompute
  5. 2026-08-14 09:04 UTCGHSA enrichment
  6. 2026-08-13 22:00 UTCEPSS rescore
  7. 2026-08-13 21:05 UTCGHSA enrichment
  8. 2026-08-13 09:06 UTCGHSA enrichment
  9. 2026-08-12 21:07 UTCGHSA enrichment
  10. 2026-08-12 16:36 UTCEG score recompute
  11. 2026-08-12 16:36 UTCGHSA enrichment
  12. 2026-08-12 13:50 UTCEPSS rescore
  13. 2026-08-12 04:36 UTCGHSA enrichment
  14. 2026-08-11 16:37 UTCEG score recompute
  15. 2026-08-11 16:37 UTCGHSA enrichment
  16. 2026-08-11 13:42 UTCEPSS rescore
  17. 2026-08-11 04:36 UTCEG score recompute
  18. 2026-08-11 04:36 UTCGHSA enrichment
  19. 2026-08-11 00:00 UTCEPSS rescore
  20. 2026-08-10 16:37 UTCGHSA enrichment
  21. 2026-08-10 04:27 UTCGHSA enrichment
  22. 2026-08-09 16:28 UTCEG score recompute
  23. 2026-08-09 16:28 UTCGHSA enrichment
  24. 2026-08-09 13:46 UTCEPSS rescore
  25. 2026-08-09 04:29 UTCGHSA enrichment
  26. 2026-08-08 16:30 UTCGHSA enrichment
  27. 2026-08-08 04:30 UTCGHSA enrichment
  28. 2026-08-07 16:31 UTCEG score recompute
  29. 2026-08-07 16:31 UTCGHSA enrichment
  30. 2026-08-07 04:32 UTCGHSA enrichment
  31. 2026-08-06 16:33 UTCEG score recompute
  32. 2026-08-06 16:33 UTCGHSA enrichment
  33. 2026-08-06 16:30 UTCNVD updateCVSS v4 → 5.5
  34. 2026-08-06 15:31 UTCMITRE cvelistV5CVSS v4 → 6.9
  35. 2026-08-06 15:22 UTCEG score recompute
  36. 2026-08-06 15:22 UTCGHSA enrichment
  37. 2026-08-06 13:46 UTCEPSS rescore
  38. 2026-08-06 03:23 UTCEG score recompute
  39. 2026-08-06 03:23 UTCNVD updateCVSS v4 → 5.5
  40. 2026-08-06 03:15 UTCEG score recompute
  41. 2026-08-06 03:15 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18991?
CVE-2026-18991 is a high vulnerability published on August 6, 2026. A security vulnerability has been detected in nanocoai NanoClaw up to 2.0.64. This affects an unknown part of the file container/agent-runner/src/mcp-tools/core.ts of the component send_file. Such manipulation leads to path traversal. The attack can be executed remotely. The exploit has been…
When was CVE-2026-18991 disclosed?
CVE-2026-18991 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-2026-18991 actively exploited?
CVE-2026-18991 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 59.6% of all scored CVEs.
What is the CVSS score of CVE-2026-18991?
CVE-2026-18991 has a CVSS v3 base score of 7.3 (NVD).
How do I remediate CVE-2026-18991?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18991, 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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