HKUDS nanobot Login-shell Environment shell.py ExecTool._prepare_command information disclosure
A flaw has been found in HKUDS nanobot up to 0.2.1. The impacted element is the function ExecTool._prepare_command of the file nanobot/agent/tools/shell.py of the component Login-shell Environment Handler. Executing a manipulation can lead to information disclosure. The attack requires local access. The exploit has been published and may be used. Upgrading to version 0.3.0 is sufficient to resolve this issue. This patch is called 4525. The affected component should be upgraded. Multiple issues were reported to the project. They reacted with a high level of professionalism and kindness: "The report concerns shell startup files reintroducing environment variables when command execution defaults to a login shell. The default was changed so exec does not use a login shell unless explicitly requested".
- Published
- Aug 7, 2026
- Updated
- Aug 12, 2026
- EPSS
- 0.2% · 6th percentile
- CWE
- CWE-200
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Report tools
Action score
7
Monitor
Low priority for now.
- CVSS
- 7 / 40 · 1.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · VulDB
- 4.8
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/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.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
—
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
- CVE-2026-49139Nanobot < 0.2.1 SSRF via Microsoft Teams Channel serviceUrl Poisoning28Monitor
- CVE-2026-90809HKUDS nanobot ExecTool shell.py ExecTool._spawn argument injection27Monitor
- CVE-2026-90808HKUDS nanobot ExecTool shell.py ExecTool._spawn incomplete blacklist21Monitor
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
- Someone with local access to the system 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
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-200 · Exposure of Sensitive Information to an Unauthorized ActorCVSS vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/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
Root cause
The extension requests broader permissions than its function needs and sends the data it collects out for purposes beyond its stated function.
The bug in code
The whole CWE-200 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
{ "permissions": ["tabs", "<all_urls>"], "background": { "service_worker": "analytics.js" }}Fixed
{ "permissions": ["activeTab"], "host_permissions": ["https://yildiz.example/*"]}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)
- ExcavationCAPEC-116likelihood: High · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- FootprintingCAPEC-169likelihood: High · Very Low
- Exploiting Trust in ClientCAPEC-22likelihood: High · High
- FingerprintingCAPEC-224likelihood: High · Very Low
- ICMP Echo Request PingCAPEC-285likelihood: Medium · Low
- TCP SYN ScanCAPEC-287Low
- Enumerate Mail Exchange (MX) RecordsCAPEC-290Low
ATT&CK techniques
- System Service DiscoveryT1007
- System Network Configuration DiscoveryT1016
- Remote System DiscoveryT1018
- System Owner/User DiscoveryT1033
- Masquerading: Match Legitimate Name or LocationT1036.005
- Network Service ScanningT1046
- System Network Connections DiscoveryT1049
- Process DiscoveryT1057
- Permission Groups DiscoveryT1069
- System Information DiscoveryT1082
- File and Directory DiscoveryT1083
- Account DiscoveryT1087
- Multi-Factor Authentication InterceptionT1111
- Peripheral Device DiscoveryT1120
- System Time DiscoveryT1124
- Access Token Manipulation:Token Impersonation/TheftT1134.001
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- gist.github.com/YLChen-007/b25f3f185478e0b2cd0e727bf5c5ed9b
- github.com/HKUDS/nanobot/
- github.com/HKUDS/nanobot/issues/4518
- github.com/HKUDS/nanobot/pull/4525
- github.com/HKUDS/nanobot/releases/tag/v0.3.0
- vuldb.com/cve/CVE-2026-19245
- vuldb.com/submit/865117
- vuldb.com/vuln/386999
- vuldb.com/vuln/386999/cti
Vendor advisories and official records. Exploit/PoC links are deliberately left out.