CVE-2026-19243: HKUDS nanobot Shell Allowlist shell.py ExecTool._spawn os command injection
Noroxi assessment
Priority: Monitor (action score 9/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 2.2% (FIRST EPSS); higher than 82.8% of all records.
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: HKUDS nanobot 0.3.0.
- Severity is disputed: the assigning authority (CNA) scores it 5.3, NVD 2.1.
Low priority for now. Upgrade to HKUDS nanobot 0.3.0 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
A security vulnerability has been detected in HKUDS nanobot up to 0.2.1. Impacted is the function ExecTool._guard_command/ExecTool._spawn of the file nanobot/agent/tools/shell.py of the component Shell Allowlist Handler. Such manipulation leads to os command injection. The attack can be executed remotely. The exploit has been disclosed publicly and may be used. Upgrading to version 0.3.0 is recommended to address this issue. The name of the patch is 4562. It is advisable to upgrade the affected component. Multiple issues were reported to the project. They reacted with a high level of professionalism and kindness: "These five reports are variants of the same root cause: validation of shell commands containing multiple segments, wrappers, comments, or chained commands. The issue was fixed by validating every executable shell segment against the configured allowlist".
- Published
- Aug 7, 2026
- Updated
- Oct 23, 2026
- EPSS
- 2.2% · 82th percentile
- CWE
- CWE-77
Report tools
Action score
9
Monitor
Low priority for now.
- CVSS
- 8 / 40 · 2.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · VulDB
- 5.3
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulDB). Independent of NVD's CPE analysis and usually ahead of it.
HKUDS nanobot
- 0.3.0not affected
- 0.2.0, 0.2.1affected
Same product
hkuds: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-2577Nanobot Unauthenticated WhatsApp Session Hijack via WebSocket Bridge40Plan
- CVE-2026-92576HKUDS nanobot before 0.3.0 Server-Side Request Forgery via WebFetchTool36Monitor
- CVE-2026-48716nanobot: Path traversal via unsanitized WhatsApp document fileName enables arbitrary file write34Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-49140Jun 1, 2026 · Nanobot < 0.2.1 Denial of Service via Matrix Media Download Handler21Monitor
- ← EarlierCVE-2026-49138Jun 1, 2026 · Nanobot < 0.2.1 SSRF via web_fetch Tool Redirect Following21Monitor
- Later →CVE-2026-19244Aug 7, 2026 · HKUDS nanobot MCP enabledTools Scope mcp.py connect_mcp_servers access control8Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| HKUDS nanobot | 0.3.0 · description | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- VulDB CNA Teamcoordinator
- Eric-c (VulDB User)reporter
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
—
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
- CVE-2026-2577172 days apartNanobot Unauthenticated WhatsApp Session Hijack via WebSocket Bridge40Plan
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-77 · Improper Neutralization of Special Elements used in a Command ('Command Injection')CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- LDAP InjectionCAPEC-136likelihood: High · High
- Command DelimitersCAPEC-15likelihood: High · High
- IMAP/SMTP Command InjectionCAPEC-183Medium
- Command InjectionCAPEC-248likelihood: Medium · High
- Manipulating Writeable Terminal DevicesCAPEC-40likelihood: High · Very High
- Exploiting Multiple Input Interpretation LayersCAPEC-43likelihood: Medium · High
- Manipulating Writeable Configuration FilesCAPEC-75likelihood: High · Very High
- Manipulating Web Input to File System CallsCAPEC-76likelihood: High · Very High
ATT&CK techniques
—
Change log
- Fix✗ → ✓
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References
Show all references (12 more)Show less
- github.com/HKUDS/nanobot/
- github.com/HKUDS/nanobot/issues/4521
- github.com/HKUDS/nanobot/pull/4562
- github.com/HKUDS/nanobot/releases/tag/v0.3.0
- vuldb.com/cve/CVE-2026-19243
- vuldb.com/submit/865112
- vuldb.com/submit/865114
- vuldb.com/submit/865115
- vuldb.com/submit/865119
- vuldb.com/submit/865121
- vuldb.com/vuln/386997
- vuldb.com/vuln/386997/cti
Vendor advisories and official records. Exploit/PoC links are deliberately left out.