CVE-2026-5789

High

Published: 21 April 2026

Published

21 April 2026

Modified

22 April 2026

KEV Added

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Patch

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CVSS Score 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0001 3.0th percentile

Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-5789 is a high-severity Unquoted Search Path or Element (CWE-428) vulnerability in Civetweb Project Civetweb. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception by Unquoted Path (T1574.009); ranked at the 3.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 CM-6 (Configuration Settings) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Path Interception by Unquoted Path (T1574.009). What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

CM-6 Configuration Settings good match

prevent

Enforces secure configuration settings for services, requiring quoted executable paths to directly prevent unquoted search path hijacking in CivetWeb service configurations.

SI-2 Flaw Remediation good match

prevent

Provides for identification, reporting, and remediation of flaws like CVE-2026-5789, including applying fixes such as quoting service paths or patching CivetWeb.

AC-6 Least Privilege partial match

prevent

Enforces least privilege on services like CivetWeb, limiting the impact of privilege escalation even if an attacker exploits the unquoted path vulnerability.

MITRE ATT&CK Enterprise TechniquesAI

T1574.009 Path Interception by Unquoted Path Stealth

Adversaries may execute their own malicious payloads by hijacking vulnerable file path references.

attack.mitre.org →

Why these techniques?

Unquoted service path vulnerability directly enables path interception by allowing placement of malicious executable in preceding directories during service startup, matching T1574.009.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Vulnerability related to an unquoted search path in CivetWeb v1.16. This vulnerability allows a local attacker to execute arbitrary code with elevated privileges by placing a malicious executable in a directory that is scanned before the intended application path (C:\Program…

Files\CivetWeb\CivetWeb.exe --), due to the absence of quotes in the service configuration.

Deeper analysisAI

CVE-2026-5789 is an unquoted search path vulnerability (CWE-428) affecting CivetWeb version 1.16. The issue stems from the service configuration lacking quotes around the executable path "C:\Program Files\CivetWeb\CivetWeb.exe", causing the system to scan preceding directories for matching executables during service startup.

A local attacker with low privileges (PR:L) can exploit this vulnerability with low complexity (AC:L) and no user interaction (UI:N). By placing a malicious executable named CivetWeb.exe in a directory scanned before C:\Program Files\CivetWeb, the attacker achieves arbitrary code execution with elevated privileges, potentially compromising confidentiality, integrity, and availability (C:H/I:H/A:H). The CVSS v3.1 base score is 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

The INCIBE-CERT advisory at https://www.incibe.es/en/incibe-cert/notices/aviso/search-path-without-quotes-civetweb provides details on the vulnerability, including recommendations for mitigation.