Cyber Resilience

CVE-2026-6823

Hkuds Openharness ≤ 0.1.7

Public PoC
Published
21 April 2026
Modified
07 May 2026
Patch / advisory
CVSS Score v4 8.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/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
EPSS Score 0.0034 27th percentile
Risk Priority 43 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-6823 is a high-severity Incorrect Default Permissions (CWE-276) vulnerability in Hkuds Openharness. Its CVSS base score is 8.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Services File Permissions Weakness (T1574.010); ranked at the 27th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-6823 is an insecure default configuration vulnerability (CWE-276) affecting HKUDS OpenHarness versions prior to the remediation in Pull Request #147. In these versions, remote channels inherit a default allow_from = ["*"] setting, which permits arbitrary remote senders to bypass admission checks. This flaw has a CVSS v3.1 base score of 8.2 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N), indicating high confidentiality impact with low complexity and no required privileges.

Attackers who can reach the configured remote channel over the network can exploit this vulnerability to bypass access controls and interact with host-backed agent runtimes. Successful exploitation enables unauthorized file disclosure and read access through default-enabled read-only tools, potentially exposing sensitive data on the host system.

Mitigation is available via Pull Request #147, which addresses the insecure default by remediating the allow_from configuration inheritance. Users should update to OpenHarness release v0.1.7 or apply the fix from commit fab40c6eabfb15f2bdf23cddd3cfe66a64ea203d. Additional details are provided in the VulnCheck advisory.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

HKUDS OpenHarness prior to PR #147 remediation contains an insecure default configuration vulnerability where remote channels inherit allow_from = ["*"] permitting arbitrary remote senders to pass admission checks. Attackers who can reach the configured channel can bypass access controls and…

more

reach host-backed agent runtimes, potentially leading to unauthorized file disclosure and read access through default-enabled read-only tools.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1574.010 Services File Permissions Weakness Stealth
Adversaries may execute their own malicious payloads by hijacking the binaries used by services.
T1543 Create or Modify System Process Persistence
Adversaries may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence.
T1554 Compromise Host Software Binary Persistence
Adversaries may modify host software binaries to establish persistent access to systems.
T1574 Hijack Execution Flow Stealth
Adversaries may execute their own malicious payloads by hijacking the way operating systems run programs.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-6819Same product: Hkuds Openharness
CVE-2026-40516Same product: Hkuds Openharness
CVE-2026-40515Same product: Hkuds Openharness
CVE-2026-6729Same product: Hkuds Openharness
CVE-2026-40503Same product: Hkuds Openharness
CVE-2026-40502Same product: Hkuds Openharness
CVE-2026-7551Same product: Hkuds Openharness
CVE-2024-27461Shared CWE-276
CVE-2023-52362Shared CWE-276
CVE-2023-46743Shared CWE-276

Affected Assets

hkuds
openharness
≤ 0.1.7

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 7 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

Enforces approved authorizations on files and resources so overly permissive defaults cannot be exploited.

Requires least-privilege defaults so that installed files are not world-writable by default.

Requires documented, restrictive configuration settings that cover file and directory permissions.

Enforces access restrictions on changes, including permission settings applied during installation or configuration.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.AM-08 partial match
prevents

Lifecycle management can encompass permission settings, yet the control is too broad to specifically mitigate incorrect defaults.

PR.AA-05 partial match
prevents

Defining and enforcing least-privilege access permissions directly prevents overly permissive defaults at install time.

PR.PS-01 partial match
prevents

Hardened baselines and configuration management explicitly require correct default file permissions.

PR.PS-06 partial match
prevents

Secure SDLC practices include establishing secure defaults, but address only the development-phase portion of the weakness.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Standard templates that restrict access to utility programs and host parameter settings prevent the assignment of overly permissive default permissions on critical resources.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Windows Server 2016 (2 rules)
  • V-224833 Permissions for program file directories must conform to minimum requirements. prevents CWE-276
  • V-224834 Permissions for the Windows installation directory must conform to minimum requirements. prevents CWE-276
Windows Server 2019 (2 rules)
  • V-205735 Windows Server 2019 permissions for program file directories must conform to minimum requirements. prevents CWE-276
  • V-205736 Windows Server 2019 permissions for the Windows installation directory must conform to minimum requirements. prevents CWE-276

References