Cyber Resilience

CVE-2026-73661

Published
13 August 2026
Modified
18 September 2026
CVSS Score v4 8.6
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/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 38 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-2026-73661 is a high-severity External Control of System or Configuration Setting (CWE-15) vulnerability. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception by PATH Environment Variable (T1574.007); ranked at the 27th 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 AC-6 (Least Privilege) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A02:2025 Security Misconfiguration

EU & UK References

Vulnerability Data

FreePBX is an open source IP PBX. Prior to 16.0.47 and 17.0.30, the FreePBX Framework module permits a crafted backup to restore the hidden AUTHTYPE setting with the value none through runRestore() in amp_conf/htdocs/admin/libraries/Builtin/Restore.php. An authenticated user with sufficient backup-restore…

more

access or write access to backup files can thereby disable FreePBX authentication during restoration, bypassing the user-interface removal of AUTHTYPE=none. This issue is fixed in versions 16.0.47 and 17.0.30.

CWE(s)
CWE-15

Related Threats

MITRE ATT&CK Enterprise Techniques

T1574.007 Path Interception by PATH Environment Variable Stealth
Adversaries may execute their own malicious payloads by hijacking environment variables used to load libraries.
attack.mitre.org →
T1547.004 Winlogon Helper DLL Persistence
Adversaries may abuse features of Winlogon to execute DLLs and/or executables when a user logs in.
attack.mitre.org →
T1547.014 Active Setup Persistence
Adversaries may achieve persistence by adding a Registry key to the Active Setup of the local machine.
attack.mitre.org →
T1574.006 Dynamic Linker Hijacking Stealth
Adversaries may execute their own malicious payloads by hijacking environment variables the dynamic linker uses to load shared libraries.
attack.mitre.org →
T1647 Plist File Modification Defense Impairment
Adversaries may modify property list files (plist files) to enable other malicious activity, while also potentially evading and bypassing system defenses.
attack.mitre.org →
T1037 Boot or Logon Initialization Scripts Persistence
Adversaries may use scripts automatically executed at boot or logon initialization to establish persistence.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-51543Shared CWE-15
CVE-2026-44768Shared CWE-15
CVE-2024-39793Shared CWE-15
CVE-2026-0232Shared CWE-15
CVE-2026-1784Shared CWE-15
CVE-2026-0495Shared CWE-15
CVE-2024-54097Shared CWE-15
CVE-2025-27889Shared CWE-15
CVE-2024-39799Shared CWE-15
CVE-2025-41452Shared CWE-15

Affected Assets

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

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

—

Mitigating Controls (NIST 800-53 r5) AI

AC-3 Access Enforcement good match

Enforces approved authorizations for logical access to configuration resources so external parties cannot alter them.

CM-5 Access Restrictions for Change good match

Enforces documented access restrictions on all changes to system configuration, directly blocking unauthorized external control of settings.

AC-6 Least Privilege good match

Limits privileges to the minimum needed, reducing the set of users who can externally modify 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.RA-07 partial match
prevents

Formal change and exception management catches externally driven configuration alterations.

PR.AA-05 partial match
prevents

Least-privilege access policies reduce unauthorized external modification of configuration values.

PR.PS-01 partial match
prevents

Hardened configuration baselines and change controls directly limit external manipulation of settings.

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.

A.5.15 Access control partial match
prevents

Access control policies underpin the technical restrictions on configuration changes.

A.5.18 Access rights partial match
prevents

Access rights assignment determines who may change system settings.

A.5.37 Documented operating procedures partial match
mitigates

Documented operating procedures define how configuration changes must be performed.

A.8.18 Use of privileged utility programs partial match
prevents

Use of privileged utility programs is controlled to prevent misuse of configuration tools.

A.8.19 Installation of software on operational systems partial match
mitigates

Restricting software installation limits unauthorized changes to configuration.

A.8.2 Privileged access rights partial match
prevents

Privileged access rights reduce the number of users who can alter configuration.

References