CVE-2026-76861: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-hj8p-w4gv-7pjf
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CVSS 8.8
CWE-121
Published
Advisory Summary

CVE-2026-76861 is a HIGH (CVSS 8.8) security vulnerability vulnerability (CWE-121: Stack-based Buffer Overflow) affecting Software libraries in the Maven ecosystem. The weakness occurs when 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).. Remediation is available in the latest vendor maintenance releases.

CVE-2026-76861 at a Glance

CVE Identifier CVE-2026-76861
GHSA Identifier GHSA-hj8p-w4gv-7pjf
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-121: Stack-based Buffer Overflow
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-76861

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-76861, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-121: Stack-based Buffer Overflow, where 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). In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

References

NVD — CVE-2026-76861 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-76861
Software Source Repository REPOSITORY
https://github.com/draw-ctf/netcore-router-public-refs/blob/main/2026.08.19-netcore-nr255v-tcpdump-overflow.md
www.vulncheck.com/advisories/netcore-... WEB
https://www.vulncheck.com/advisories/netcore-nr255-v-1.5.130703-stack-based-buffer-overflow-in-ntools-tcpdump-start-set-cgi

Frequently Asked Questions

What is CVE-2026-76861?
CVE-2026-76861 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-121: Stack-based Buffer Overflow.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-76861?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-76861?
CVE-2026-76861 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-76861?
CVE-2026-76861 is classified under CWE-121: Stack-based Buffer Overflow (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).).
How can I check Maven dependencies for CVE-2026-76861?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hj8p-w4gv-7pjf",
  "modified" : "2026-09-16T00:31:30Z",
  "published" : "2026-09-16T00:31:30Z",
  "aliases" : [ "CVE-2026-76861" ],
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/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"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-76861"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/draw-ctf/netcore-router-public-refs/blob/main/2026.08.19-netcore-nr255v-tcpdump-overflow.md"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/netcore-nr255-v-1.5.130703-stack-based-buffer-overflow-in-ntools-tcpdump-start-set-cgi"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-121" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-15T22:17:00Z"
  }
}