CVE-2025-9938: A weakness has been identified in D-Link DI-8400 16.07.26A1

This month

HIGH 8.8MITIGATE

CVE-2025-9938 is a high-severity flaw (CVSS 8.8) affecting di-8400 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A weakness has been identified in D-Link DI-8400 16.07.26A1. The affected element is the function yyxz_dlink_asp of the file /yyxz.asp. This manipulation of the argument ID causes stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be exploited.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.6% (top 24%)
CISA exploited list	No
Weakness	CWE-119, CWE-121, CWE-787
Published	2025-09-04
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: dlink

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-09-04 10:42 UTCPublished CVE record published
2026-06-17 10:10 UTCUpdated Record last modified

dlink di-8400 firmware MITIGATE

Affected: 16.07.26a1

Fixed in: no fixed release known

Safe to downgrade to: a release before 16.07.26a1

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · pipx · FIXED · 1.18.9-1.fc46 · FEDORA-2026-95305954ab · source

sudo dnf upgrade --advisory=FEDORA-2026-95305954ab

Fedora ELN · libisds · FIXED · 0.11.2-19.eln159 · FEDORA-2026-bf61b68668 · source

sudo dnf upgrade --advisory=FEDORA-2026-bf61b68668

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/ZZ2266/.github.io/tree/main/Dlink/DI-8400/yyxz.asp
Write-up: github.com/ZZ2266/.github.io/tree/main/Dlink/DI-8400/yyxz.asp#proof-of-concept-poc

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-9938?

di-8400 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-9938 being exploited?

CVE-2025-9938 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-9938 affect?

CVE-2025-9938 affects di-8400 firmware. Severity is high (CVSS 8.8). A weakness has been identified in D-Link DI-8400 16.07.26A1. The affected element is the function yyxz_dlink_asp of the file /yyxz.asp. This manipulation of the argument ID causes stack-based buffer overflow. It is possible to initiate the

How urgent is CVE-2025-9938?

Priority 55/100. High severity; Public exploit reference

Software pages

D-Link vulnerabilities

Related CVEs

CVE-2025-8175 MEDIUM 6.5 MITIGATE A vulnerability was found in D-Link DI-8400 16.07.26A1
CVE-2024-52739 HIGH 8.0 MITIGATE D-LINK DI-8400 v16.07.26A1 was discovered to contain multiple remote command execution (RCE) vulnerabilities i
CVE-2024-44400 CRITICAL 9.8 MITIGATE A vulnerability was discovered in DI_8400-16.07.26A1, which has been classified as critical

References

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