Cyber Resilience

CVE-2026-4831

Auth Bypass

Published
26 March 2026
Modified
24 April 2026
CVSS Score v4 6.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:H/AT:N/PR:N/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
EPSS Score 0.0048 39th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-4831 is a medium-severity Improper Authentication (CWE-287) vulnerability in Wetolink (inferred from references). Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 39th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and IA-8 (Identification and Authentication (Non-organizational Users)) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A security flaw has been discovered in kalcaddle kodbox 1.64. Impacted is the function can of the file /workspace/source-code/app/controller/explorer/auth.class.php of the component Password-protected Share Handler. Performing a manipulation results in improper authentication. The attack is possible to be carried out…

more

remotely. The complexity of an attack is rather high. The exploitability is considered difficult. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Improper authentication (CWE-287) in remote password-protected share handler of public-facing web app directly enables exploitation of the application for unauthorized access.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-5270Shared CWE-287
CVE-2026-10167Shared CWE-287
CVE-2024-0799Shared CWE-287
CVE-2025-68402Shared CWE-287
CVE-2026-34873Shared CWE-287
CVE-2026-15542Shared CWE-287
CVE-2026-56353Shared CWE-287
CVE-2026-23813Shared CWE-287
CVE-2026-56237Shared CWE-287
CVE-2026-8305Shared CWE-287

Affected Assets

Wetolink
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • IA-8 Identification and Authentication (Non-organizational Users)
  • AC-17 Remote Access
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 8 hardening rules · 5 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.4
  • V6.5.4
  • V6.5.5
  • V6.5.7

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces authentication decisions before allowing access to password-protected shares, blocking the improper-auth bypass in auth.class.php.

prevent

Requires proper identification and authentication for non-organizational users accessing shared resources, addressing the CWE-287 flaw in the share handler.

AC-17 Remote Access partial match
prevent

Mandates authentication controls for all remote access paths used to reach the vulnerable password-protected share endpoint.

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.

PR.AA-03 mostly match
prevents

PR.AA-03 directly enforces authentication mechanisms that eliminate most improper-authentication defects, yet CWE-287 spans additional vectors (missing checks, flawed protocols, session handling) that one control does not fully close.

PR.AA-04 mostly match
prevents

PR.AA-04 directly enables verification of identity assertions (mostly preventing CWE-287 in that scope) yet leaves many other authentication failure modes unaddressed (only partial prevention overall).

PR.AA-01 partial match
prevents

PR.AA-01 supplies and governs credentials/tokens that authentication relies on, removing some weak-credential cases, yet leaves verification logic, missing checks, and protocol flaws untouched.

PR.AA-02 partial match
prevents

PR.AA-02 ensures valid enrollment and unique credential binding, which reduces some improper-auth risks at issuance time but leaves runtime claim verification untouched, so each direction only partially addresses the other.

PR.PS-01 partial match
prevents

PR.PS-01 can enforce auth-related settings via hardened baselines and default reviews, blocking some config-based instances of CWE-287, yet leaves code-level auth flaws untouched so neither direction reaches mostly.

PR.PS-02 partial match
prevents

Patching/maintenance can remediate some known auth vulnerabilities after deployment (partial forward) but does not address the design or implementation of authentication logic itself (none reverse).

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

Requiring authentication methods whose strength matches the sensitivity of the data and mandating multi-factor authentication directly blocks attempts to access resources without proving identity.

prevents

Verifying user identity before issuing replacement credentials and forcing changes after compromise reduces the likelihood that authentication bypass can be achieved through stolen or weak credentials.

prevents

Mandating segregated approval and oversight for non-human identities reduces the chance that weak or orphaned credentials can be exploited for unauthorized authentication.

mitigates

Requiring authentication mechanisms and technical parameters for secure connections ensures that network services verify user identity before granting access, preventing exploitation of missing or weak authentication.

prevents

Security requirements specified early and verified through testing drive the consistent implementation of authentication mechanisms, decreasing the likelihood that authentication steps are omitted or incorrectly applied.

prevents

Defining the required level of trust in entity identity and the authentication mechanisms to achieve it ensures that authentication is explicitly addressed rather than omitted.

References