# CVE-2026-1685: D-Link DIR-823X Login sub_40AC74 excessive authentication

> Remote attackers can bypass login rate limiting on D-Link DIR-823X routers, facilitating brute-force attacks despite high complexity.

- **Severity:** Medium 6.3 (`CVSS: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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 Jan 2026
- **Updated:** 23 Feb 2026
- **Also known as:** GHSA-4h4g-2r65-5v68

## What is CVE-2026-1685?

CVE-2026-1685 is a medium-severity vulnerability in D-Link DIR-823X, published on 30 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

Weakness: CWE-799 (Improper Control of Interaction Frequency), CWE-307 (Improper Restriction of Excessive Authentication Attempts)

## Which versions are affected by CVE-2026-1685?

It affects 1 product.


Products: Dlink Dir-823x Firmware.

## How do I fix CVE-2026-1685?

No fix has been published for CVE-2026-1685 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-1685 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-1685 exists.

## Other vulnerabilities in D-Link DIR-823X

- [CVE-2025-29635](https://insights.sbomify.com/CVE-2025-29635/): D-Link DIR-823X Command Injection (high 7.2, exploited in the wild)
- [CVE-2025-29040](https://insights.sbomify.com/CVE-2025-29040/): Command injection in n/a (critical 9.8)
- [CVE-2025-29041](https://insights.sbomify.com/CVE-2025-29041/): Command injection in n/a (critical 9.8)
- [CVE-2025-29042](https://insights.sbomify.com/CVE-2025-29042/): Command injection in n/a (critical 9.8)
- [CVE-2025-29043](https://insights.sbomify.com/CVE-2025-29043/): Command injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-1685 and fix it if it is affected.

What it is: CVE-2026-1685 is a medium-severity vulnerability in D-Link DIR-823X, published on 30 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-1685 exists.

Affected product: D-Link DIR-823X. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-1685/ (Markdown: https://insights.sbomify.com/CVE-2026-1685/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-1685
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-1685
- OSV: https://osv.dev/vulnerability/CVE-2026-1685

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-1685/
Summaries are generated and may contain mistakes; the official description above is the record.