Cyber Resilience

CVE-2026-1685

Dlink Dir-823X Firmware 250416

Published
30 January 2026
Modified
20 February 2026
Patch / advisory
View advisory
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 0.0099 59th percentile
Risk Priority 33 floored blend · peak EPSS

Summary

CVE-2026-1685 is a medium-severity Improper Restriction of Excessive Authentication Attempts (CWE-307) vulnerability in Dlink Dir-823X Firmware. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Brute Force (T1110); ranked in the top 41% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-10 (Concurrent Session Control) and AC-7 (Unsuccessful Logon Attempts) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A06:2025 Insecure DesignA07:2025 Authentication Failures

EU & UK References

Vulnerability Data

A vulnerability was identified in D-Link DIR-823X 250416. This vulnerability affects the function sub_40AC74 of the component Login. Such manipulation leads to improper restriction of excessive authentication attempts. The attack may be performed from remote. This attack is characterized by…

more

high complexity. It is stated that the exploitability is difficult. The exploit is publicly available and might be used.

CWE(s)
CWE-307CWE-799

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 →
T1499.002 Service Exhaustion Flood Impact
Adversaries may target the different network services provided by systems to conduct a denial of service (DoS).
attack.mitre.org →
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
attack.mitre.org →
T1667 Email Bombing Impact
Adversaries may flood targeted email addresses with an overwhelming volume of messages.
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 →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-1103Same product: Dlink Dir-823X
CVE-2025-0492Same product: Dlink Dir-823X
CVE-2026-1544Same product: Dlink Dir-823X
CVE-2025-11100Same product: Dlink Dir-823X
CVE-2026-2129Same product: Dlink Dir-823X
CVE-2025-10401Same product: Dlink Dir-823X
CVE-2025-11096Same product: Dlink Dir-823X
CVE-2025-11099Same product: Dlink Dir-823X
CVE-2026-2120Same product: Dlink Dir-823X
CVE-2026-2175Same product: Dlink Dir-823X

Affected Assets

dlink
dir-823x firmware
250416

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.

AC-10 Concurrent Session Control good match

ac-10 enforces a hard limit on concurrent sessions per user, directly stopping uncontrolled interaction frequency at the session level.

SC-5 Denial-of-service Protection partial match

sc-5 reduces the impact of excessive request volume (DoS) but does not itself impose the frequency controls whose absence defines 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.IR-01 partial match
prevents

Protecting networks from unauthorized usage can incorporate rate limiting to bound interaction frequency.

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.8.20 Networks security partial match
mitigates

Network security controls can enforce rate limiting and throttling at the perimeter.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly include controls on interaction frequency and throttling.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles recommend rate-limiting and resource-management mechanisms.

A.8.28 Secure coding partial match
prevents

Secure coding practices can embed input-frequency and throttling checks in code.

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.

A.8.6 Capacity management partial match
degrades

Capacity management directly limits request rates and resource exhaustion that CWE-799 describes.

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` (authoritative rows only; rows rated `none` are excluded).

RHEL 7 (2 rules)
  • V-204427 The Red Hat Enterprise Linux operating system must be configured to lock accounts for a minimum of 15 minutes after three unsuccessful logon attempts within a 15-minute timeframe. prevents CWE-307
  • V-204428 The Red Hat Enterprise Linux operating system must lock the associated account after three unsuccessful root logon attempts are made within a 15-minute period. prevents CWE-307

References