Cyber Resilience

CVE-2026-16347

Published
28 July 2026
Modified
30 July 2026
CVSS Score v4 8.7
Click a component to see what it means
Raw vectorCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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 0.0023 14th percentile
Risk Priority 37 floored blend · peak EPSS

Summary

CVE-2026-16347 is a high-severity Improper Restriction of Excessive Authentication Attempts (CWE-307) vulnerability in Cisa (inferred from references). Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Brute Force (T1110); ranked at the 14th 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-7 (Unsuccessful Logon Attempts) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability Data

MikroTik RouterOS contains a weakness in its API authentication handling that lacks effective safeguards against excessive login attempts. The system does not enforce meaningful rate-limiting, account lockout, or source-based restrictions, allowing repeated authentication failures to proceed without defensive response. In…

more

some versions, a fixed per-connection delay is present, but it can be bypassed through concurrent sessions, resulting in continued high-volume attempts. This deficiency increases the risk that an attacker could eventually obtain valid credentials and gain unauthorized access to administrative services.

CWE(s)
CWE-307

Related Threats

MITRE ATT&CK Enterprise Techniques

T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
attack.mitre.org →
T1110.001 Password Guessing Credential Access
Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts.
attack.mitre.org →
T1110.003 Password Spraying Credential Access
Adversaries may use a single or small list of commonly used passwords against many different accounts to attempt to acquire valid account credentials.
attack.mitre.org →
T1110.004 Credential Stuffing Credential Access
Adversaries may use credentials obtained from breach dumps of unrelated accounts to gain access to target accounts through credential overlap.
attack.mitre.org →
T1078 Valid Accounts Stealth
Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-25595Shared CWE-307
CVE-2025-22645Shared CWE-307
CVE-2026-31851Shared CWE-307
CVE-2026-27778Shared CWE-307
CVE-2026-43914Shared CWE-307
CVE-2024-41904Shared CWE-307
CVE-2024-39874Shared CWE-307
CVE-2026-20882Shared CWE-307
CVE-2023-32074Shared CWE-307
CVE-2023-3548Shared CWE-307

Affected Assets

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

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

AC-7 Unsuccessful Logon Attempts good match

AC-7 directly enforces limits on consecutive failed logons, structurally blocking brute-force exploitation of the weakness.

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

Authentication enforcement directly includes lockout, throttling, and MFA policies that prevent brute-force attempts.

DE.CM-03 partial match
prevents

Behavioral monitoring of authentication activity can detect excessive failed attempts after they occur.

PR.PS-04 partial match
prevents

Generating auth logs enables later detection or forensics but does not itself restrict attempts.

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.8.5 Secure authentication partial match
prevents

CAPTCHA, account lock-out after repeated failures, and alerts on excessive attempts directly stop automated brute-force guessing of credentials.

References