CVE Intelligence
High Memory corruption

CVE-2026-76861 — Netcore NR255-V 1.5.130703 Stack-Based Buffer Overflow in ntools_tcpdump_start_set.cgi

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.

Published Sep 15, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulnCheck

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.7% (30-day exploitation probability)+8
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.68%
ahead of 51% of scored CVEs · Oct 15, 2026
Affects
Netcore
NR255-V
CVSS base
8.8
High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Netcore NR255-V).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Netcore NR255-V version 1.5.130703 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
8.7 CVSS 4.0 High — — disclosure@vulncheck.com via NIST National Vulnerability Database
8.7 CVSS 4.0 High — — VulnCheck via CVE Program (cve.org) e CISA ADP
8.8 CVSS 3.1 High 2.8 5.9 disclosure@vulncheck.com via NIST National Vulnerability Database
8.8 CVSS 3.1 High — — VulnCheck via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: disclosure@vulncheck.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-121 · Stack-based Buffer Overflow

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · netcore/nr255-v
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 8.8
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Deferred
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 15, 2026 · VulnCheck

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

2 on the record

Elsewhere on this site

Netcore
every CVE for this vendor
Memory corruption
same class
CWE-121
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-92257 Netcore NR255-V 1.5.130703 Stored Cross-Site Scripting in L7 Content Management via eval() Sinks Sep 15, 2026
  • CVE-2026-92255 Netcore NR255-V 1.5.130703 Out-of-Bounds Read in filter_arp_put_file.cgi via String API Misuse Sep 15, 2026
  • CVE-2026-92256 Netcore NR255-V 1.5.130703 IPsec PSK and RSA Key Disclosure via l2tpd_config_show.cgi Read Handlers Sep 15, 2026
  • CVE-2026-76870 Netcore NR255-V 1.5.130703 Out-of-Bounds Read in mtd_write Firmware Upload Validation Sep 15, 2026
  • CVE-2026-76871 Netcore NR255-V 1.5.130703 Sensitive Information Disclosure via VPN Read Handlers Sep 15, 2026
  • CVE-2026-76872 Netcore NR255-V 1.5.130703 Stored Cross-Site Scripting via DHCP/ACL Management Pages Sep 15, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-76861 is "Netcore NR255-V 1.5.130703 Stack-Based Buffer Overflow in ntools_tcpdump_start_set.cgi", rated High. It affects NR255-V (Netcore); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 0.68% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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