CVE-2026-90809

HIGHPre-NVD 7.37.3—
EchelonGraph scoreHIGH confidence

Score 7.3 from GitHub Security Advisory published 2026-09-14. a secondary CVSS source baseline 7.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
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: None knownExposed: 0

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

A vulnerability was identified in HKUDS nanobot up to 0.2.1. The affected element is the function ExecTool._guard_command/ExecTool._spawn of the file nanobot/agent/tools/shell.py of the component ExecTool. Such manipulation leads to argument injection. It is possible to launch the attack remotely. The name of the patch is af582246f141311d574551b7571a517bcc3df750. It is best practice to apply a patch to resolve this issue.

CVSS v3
7.3
EG Score
7.3(high)
EG Risk
48(Track)
EG Risk 48/100SSVC: 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
Severity73% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
26%
KEV
Not listed

Published

September 14, 2026

Last Modified

September 15, 2026

Advisory Details (4)

Auto-updated Sep 14, 2026
Upstream fix merged — awaiting tagged release. Sources: github_pr, github_commit.
generic

GitHub - HKUDS/nanobot: Ultra-lightweight, open-source, self-hosted personal AI agent framework in Python with WebUI, tools, memory, MCP, multi-agent workflows, automation, and chat apps · GitHub

https://github.com/HKUDS/nanobot/
github_commit

commit af582246f141 (HKUDS/nanobot)

Fix landed in HKUDS/nanobot commit af582246f141 — awaiting tagged release

https://github.com/HKUDS/nanobot/commit/af582246f141311d574551b7571a517bcc3df750
github_pr

[Security] `exec.allowPatterns` shell-chain bypass allows unintended command execution

Fix merged in HKUDS/nanobot PR #5345 on 2026-08-13 — awaiting tagged release

https://github.com/HKUDS/nanobot/pull/5345
generic

[Security] `exec.allowPatterns` shell-chain bypass allows unintended command execution · Issue #5306 · HKUDS/nanobot · GitHub

https://github.com/HKUDS/nanobot/issues/5306

Vendor Advisories for CVE-2026-90809(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 27× in last 7d / 27× 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. 2026-09-19 16:02 UTCEG score recompute
  2. 2026-09-19 16:02 UTCGHSA enrichment
  3. 2026-09-19 05:12 UTCEG score recompute
  4. 2026-09-19 05:12 UTCGHSA enrichment
  5. 2026-09-18 19:28 UTCEPSS rescore
  6. 2026-09-18 18:23 UTCGHSA enrichment
  7. 2026-09-18 07:34 UTCGHSA enrichment
  8. 2026-09-17 20:44 UTCEG score recompute
  9. 2026-09-17 20:44 UTCGHSA enrichment
  10. 2026-09-17 19:32 UTCEPSS rescore
  11. 2026-09-17 09:54 UTCGHSA enrichment
  12. 2026-09-16 23:04 UTCEG score recompute
  13. 2026-09-16 23:04 UTCGHSA enrichment
  14. 2026-09-16 14:09 UTCEPSS rescore
  15. 2026-09-16 12:15 UTCEG score recompute
  16. 2026-09-16 12:15 UTCGHSA enrichment
  17. 2026-09-16 05:15 UTCEPSS rescore
  18. 2026-09-16 01:25 UTCGHSA enrichment
  19. 2026-09-15 14:35 UTCEG score recompute
  20. 2026-09-15 14:35 UTCGHSA enrichment
  21. 2026-09-15 14:03 UTCEG score recompute
  22. 2026-09-15 14:03 UTCGHSA enrichment
  23. 2026-09-15 07:52 UTCEG score recompute
  24. 2026-09-15 07:52 UTCGHSA enrichment
  25. 2026-09-14 19:19 UTCEG score recompute
Show 2 more
  1. 2026-09-14 18:25 UTCEG score recompute
  2. 2026-09-14 18:24 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-90809?
CVE-2026-90809 is a high vulnerability published on September 14, 2026. A vulnerability was identified in HKUDS nanobot up to 0.2.1. The affected element is the function ExecTool.guardcommand/ExecTool._spawn of the file nanobot/agent/tools/shell.py of the component ExecTool. Such manipulation leads to argument injection. It is possible to launch the attack remotely.…
When was CVE-2026-90809 disclosed?
CVE-2026-90809 was first published in the National Vulnerability Database on September 14, 2026, with the most recent update on September 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-90809 actively exploited?
CVE-2026-90809 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 74.1% of all scored CVEs.
What is the CVSS score of CVE-2026-90809?
CVE-2026-90809 has a CVSS v3 base score of 7.3 (NVD).
How do I remediate CVE-2026-90809?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-90809, 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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