CVE-2026-17251
Unauthenticated Denial of Service via Null Pointer Dereference in HTTP Request Parsing
Description
A NULL pointer dereference vulnerability exists in the HTTP request parsing functionality of TL-MR6400 v7. An unauthenticated remote attacker can trigger the vulnerability by sending a specially crafted HTTP request containing a malformed session cookie header. Successful exploitation may cause the HTTP service process to crash, resulting in a denial-of-service condition and temporary loss of management or CGI functionality until service recovery.
INFO
Published Date :
Aug. 21, 2026, 6:16 p.m.
Last Modified :
Oct. 14, 2026, 7:10 p.m.
Remotely Exploit :
No
Source :
f23511db-6c3e-4e32-a477-6aa17d310630
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | HIGH | f23511db-6c3e-4e32-a477-6aa17d310630 | ||||
| CVSS 4.0 | HIGH | f23511db-6c3e-4e32-a477-6aa17d310630 |
Solution
- Update TL-MR6400 v7 firmware to the latest version.
- Apply vendor security patches for HTTP request handling.
- Sanitize session cookie headers during parsing.
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-2026-17251.
| URL | Resource |
|---|---|
| https://www.tp-link.com/en/support/download/tl-mr6400/v7/#Firmware | |
| https://www.tp-link.com/tw/support/download/tl-mr6400/v7/#Firmware | |
| https://www.tp-link.com/us/support/faq/5259/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-17251 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-2026-17251
weaknesses.
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-2026-17251 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-17251 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.
-
CVE Translated by [email protected]
Oct. 14, 2026
Action Type Old Value New Value Added Translation Title: TL-MR6400 v7.0 de TP-Link Systems Inc., Description: Una vulnerabilidad de desreferencia de puntero NULL existe en la funcionalidad de análisis de solicitudes HTTP de TL-MR6400 v7. Un atacante remoto no autenticado puede activar la vulnerabilidad enviando una solicitud HTTP especialmente diseñada que contiene un encabezado de cookie de sesión malformado. La explotación exitosa puede causar que el proceso del servicio HTTP falle, lo que resulta en una condición de denegación de servicio y la pérdida temporal de la funcionalidad de gestión o CGI hasta la recuperación del servicio. -
New CVE Received by f23511db-6c3e-4e32-a477-6aa17d310630
Aug. 21, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'TP-Link Systems Inc.', 'product': 'TL-MR6400 v7.0', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.9.0 Build 260714', 'versionType': 'custom'}], 'platforms': ['Linux'], 'defaultStatus': 'unaffected'}] Added Description A NULL pointer dereference vulnerability exists in the HTTP request parsing functionality of TL-MR6400 v7. An unauthenticated remote attacker can trigger the vulnerability by sending a specially crafted HTTP request containing a malformed session cookie header. Successful exploitation may cause the HTTP service process to crash, resulting in a denial-of-service condition and temporary loss of management or CGI functionality until service recovery. Added CVSS V4.0 AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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 Added CWE CWE-476 Added Reference https://www.tp-link.com/en/support/download/tl-mr6400/v7/#Firmware Added Reference https://www.tp-link.com/tw/support/download/tl-mr6400/v7/#Firmware Added Reference https://www.tp-link.com/us/support/faq/5259/ -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 21, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-17251', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-21T17:40:25.485077Z'}