CVE-2026-76861

Deferred Deferred - Pending Action

Stack-Based Buffer Overflow in Netcore NR255-V Router

Publication date: 2026-09-15

Last updated on: 2026-09-21

Assigner: VulnCheck

Description

Netcore NR255-V version 1.5.130703 contains a stack-based buffer overflow in ntools_tcpdump_start_set.cgi caused by an unsized sprintf call when processing form values. An attacker can submit crafted input to this cgi endpoint to overflow the stack buffer and potentially execute arbitrary code.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-09-15

Last Modified

2026-09-21

Generated

2026-10-06

AI Q&A

2026-09-16

EPSS Evaluated

2026-10-04

NVD

CVE-2026-76861

EUVD

EUVD-2026-80033

Affected Vendors & Products

Vendor	Product	Version / Range
netcore	nr255-v	1.5.130703

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-121	A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).

Attack-Flow Graph

Executive Summary

This vulnerability is a stack-based buffer overflow in Netcore NR255-V version 1.5.130703. It occurs in the ntools_tcpdump_start_set.cgi component due to an unsized sprintf call when processing form values. An attacker can exploit this by sending crafted input to trigger a stack overflow, potentially allowing arbitrary code execution.

Detection Guidance

Detect this vulnerability by checking for the presence of Netcore NR255-V version 1.5.130703 or vulnerable ntools_tcpdump_start_set.cgi endpoints. Inspect network traffic for malformed requests to this CGI endpoint. Use vulnerability scanners to identify outdated firmware versions.

Impact Analysis

This vulnerability allows an attacker with network access to execute arbitrary code on the affected device. This could lead to full system compromise, data theft, or disruption of services. The high CVSS scores indicate significant risk of unauthorized access and control.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating GDPR's data protection requirements and HIPAA's security rules. Organizations using affected Netcore devices may face compliance violations, potential fines, and reputational damage due to data breaches.

Mitigation Strategies

Immediately update Netcore NR255-V to the latest patched version. Disable or restrict access to the ntools_tcpdump_start_set.cgi endpoint if possible. Apply network-level controls to block malicious input patterns targeting this CGI.

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