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9.8
CRITICAL CVSS 3.1
CVE-2025-7673
Zyxel zhttpd Web Server Buffer Overflow Vulnerability
Description

A buffer overflow vulnerability in the URL parser of the zhttpd web server in Zyxel VMG8825-T50K firmware versions prior to V5.50(ABOM.5)C0 could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and potentially execute arbitrary code by sending a specially crafted HTTP request.

INFO

Published Date :

July 16, 2025, 7:15 a.m.

Last Modified :

Jan. 14, 2026, 5:52 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]
Affected Products

The following products are affected by CVE-2025-7673 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Zyxel emg3525-t50b_firmware
2 Zyxel emg5523-t50b_firmware
3 Zyxel emg5723-t50k_firmware
4 Zyxel ex3510-b0_firmware
5 Zyxel ex5510-b0_firmware
6 Zyxel vmg3927-t50k_firmware
7 Zyxel vmg8623-t50b_firmware
8 Zyxel vmg8825-t50k_firmware
9 Zyxel vmg3625-t50b_firmware
10 Zyxel emg6726-b10a_firmware
11 Zyxel vmg1312-t20b_firmware
12 Zyxel vmg3927-b50a_firmware
13 Zyxel vmg3927-b50b_firmware
14 Zyxel vmg3927-b60a_firmware
15 Zyxel vmg4927-b50a_firmware
16 Zyxel vmg8825-b50a_firmware
17 Zyxel vmg8825-b60a_firmware
18 Zyxel xmg3927-b50a_firmware
19 Zyxel xmg8825-b50a_firmware
20 Zyxel vmg8825-t50k
21 Zyxel vmg8623-t50b
22 Zyxel vmg3927-t50k
23 Zyxel vmg3625-t50b
24 Zyxel emg5723-t50k
25 Zyxel emg5523-t50b
26 Zyxel emg3525-t50b
27 Zyxel ex5510-b0
28 Zyxel ex3510-b0
29 Zyxel emg6726-b10a
30 Zyxel vmg1312-t20b
31 Zyxel vmg3927-b50a
32 Zyxel vmg3927-b50b
33 Zyxel vmg3927-b60a
34 Zyxel vmg4927-b50a
35 Zyxel vmg8825-b50a
36 Zyxel vmg8825-b60a
37 Zyxel xmg3927-b50a
38 Zyxel xmg8825-b50a
39 Zyxel vmg4005-b50b_firmware
40 Zyxel vmg4005-b50b
41 Zyxel vmg3925-b10b_firmware
42 Zyxel vmg3925-b10b
43 Zyxel vmg3925-b10c_firmware
44 Zyxel vmg3925-b10c
45 Zyxel vmg8825-bx0b_firmware
46 Zyxel vmg8825-bx0b
47 Zyxel vmg8924-b10d_firmware
48 Zyxel vmg8924-b10d
: Total Affected Vendor : 1 | Products : 48
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL [email protected]
Solution
Update the zhttpd web server to patch the buffer overflow vulnerability.
  • Update the Zyxel VMG8825-T50K firmware.
  • Ensure the firmware version is V5.50(ABOM.5)C0 or later.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-7673.

URL Resource
https://www.zyxel.com/service-provider/global/en/zyxel-security-advisory-remote-code-execution-and-denial-service-vulnerabilities-cpe Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-7673 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-7673 weaknesses.

CAPEC-8: Buffer Overflow in an API Call Buffer Overflow in an API Call CAPEC-9: Buffer Overflow in Local Command-Line Utilities Buffer Overflow in Local Command-Line Utilities CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables CAPEC-14: Client-side Injection-induced Buffer Overflow Client-side Injection-induced Buffer Overflow CAPEC-24: Filter Failure through Buffer Overflow Filter Failure through Buffer Overflow CAPEC-42: MIME Conversion MIME Conversion CAPEC-44: Overflow Binary Resource File Overflow Binary Resource File CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-46: Overflow Variables and Tags Overflow Variables and Tags CAPEC-47: Buffer Overflow via Parameter Expansion Buffer Overflow via Parameter Expansion CAPEC-67: String Format Overflow in syslog() String Format Overflow in syslog() CAPEC-92: Forced Integer Overflow Forced Integer Overflow CAPEC-100: Overflow Buffers Overflow Buffers

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-7673 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2025-7673 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Jan. 14, 2026

    Action Type Old Value New Value
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:emg3525-t50b_firmware:*:*:*:*:emea:*:*:* versions up to (excluding) 5.50(abpm.4)c0 OR cpe:2.3:h:zyxel:emg3525-t50b:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:emg3525-t50b_firmware:*:*:*:*:america:*:*:* versions up to (excluding) 5.50(absl.0)b8 OR cpe:2.3:h:zyxel:emg3525-t50b:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:emg5523-t50b_firmware:*:*:*:*:emea:*:*:* versions up to (excluding) 5.50(abpm.4)c0 OR cpe:2.3:h:zyxel:emg5523-t50b:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:emg5523-t50b_firmware:*:*:*:*:america:*:*:* versions up to (excluding) 5.50(absl.0)b8 OR cpe:2.3:h:zyxel:emg5523-t50b:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:emg5723-t50k_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.50(abom.5)c0 OR cpe:2.3:h:zyxel:emg5723-t50k:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:emg6726-b10a_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.13(abnp.6).c OR cpe:2.3:h:zyxel:emg6726-b10a:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:ex3510-b0_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.17(abup.3)c0 OR cpe:2.3:h:zyxel:ex3510-b0:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:ex5510-b0_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.15(abqx.3)c0 OR cpe:2.3:h:zyxel:ex5510-b0:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg1312-t20b_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.50(absb.3)c0 OR cpe:2.3:h:zyxel:vmg1312-t20b:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg3625-t50b_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.50(abpm.4)c0 OR cpe:2.3:h:zyxel:vmg3625-t50b:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg3925-b10b_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.13(aavf.16)c OR cpe:2.3:h:zyxel:vmg3925-b10b:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg3925-b10c_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.13(aavf.16)c OR cpe:2.3:h:zyxel:vmg3925-b10c:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg3927-b50a_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.15(abmt.5)c0 OR cpe:2.3:h:zyxel:vmg3927-b50a:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg3927-b60a_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.15(abmt.5)c0 OR cpe:2.3:h:zyxel:vmg3927-b60a:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg3927-b50b_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.13(ably.6)c0 OR cpe:2.3:h:zyxel:vmg3927-b50b:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg3927-t50k_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.50(abom.5)c0 OR cpe:2.3:h:zyxel:vmg3927-t50k:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg4005-b50b_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.13(abrl.5)c0 OR cpe:2.3:h:zyxel:vmg4005-b50b:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg4927-b50a_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.13(ably.6)c0 OR cpe:2.3:h:zyxel:vmg4927-b50a:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg8623-t50b_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.50(abpm.4)c0 OR cpe:2.3:h:zyxel:vmg8623-t50b:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg8825-b50a_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.15(abmt.5)c0 OR cpe:2.3:h:zyxel:vmg8825-b50a:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg8825-b60a_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.15(abmt.5)c0 OR cpe:2.3:h:zyxel:vmg8825-b60a:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg8825-bx0b_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.17(abny.5)c0 OR cpe:2.3:h:zyxel:vmg8825-bx0b:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg8825-t50k_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.50(abom.5)c0 OR cpe:2.3:h:zyxel:vmg8825-t50k:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:vmg8924-b10d_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.13(abgq.6)c0 OR cpe:2.3:h:zyxel:vmg8924-b10d:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:xmg3927-b50a_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.15(abmt.5)c0 OR cpe:2.3:h:zyxel:xmg3927-b50a:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:zyxel:xmg8825-b50a_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.17(abmt.5)c0 OR cpe:2.3:h:zyxel:xmg8825-b50a:-:*:*:*:*:*:*:*
    Added Reference Type Zyxel Corporation: https://www.zyxel.com/service-provider/global/en/zyxel-security-advisory-remote-code-execution-and-denial-service-vulnerabilities-cpe Types: Vendor Advisory
  • New CVE Received by [email protected]

    Jul. 16, 2025

    Action Type Old Value New Value
    Added Description A buffer overflow vulnerability in the URL parser of the zhttpd web server in Zyxel VMG8825-T50K firmware versions prior to V5.50(ABOM.5)C0 could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and potentially execute arbitrary code by sending a specially crafted HTTP request.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-120
    Added Reference https://www.zyxel.com/service-provider/global/en/zyxel-security-advisory-remote-code-execution-and-denial-service-vulnerabilities-cpe
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 9.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact