CVE-2026-48689Network attack vector

Remote code execution via off-by-one buffer write

Published May 26, 2026 · Updated May 26, 2026

Heap-based buffer overflow in FastNetMon Community Edition 1.2.9 and earlier allows remote attackers to execute code via network traffic. Five dynamic_binary_buffer_t append and copy methods accept offset-plus-length values one byte above maximum_internal_storage_size, then copy data past the allocation. Crafted NetFlow, sFlow, IPFIX, or BGP input reaching a listening instance corrupts adjacent heap data and enables code execution as the service process.

CVSS severity9.8
Critical
EPSS probability0.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Heap-based buffer overflow in FastNetMon Community Edition 1.2.9 and earlier allows remote attackers to execute code via network traffic. Five dynamic_binary_buffer_t append and copy methods accept offset-plus-length values one byte above maximum_internal_storage_size, then copy data past the allocation. Crafted NetFlow, sFlow, IPFIX, or BGP input reaching a listening instance corrupts adjacent heap data and enables code execution as the service process.

The record

CVE
CVE-2026-48689
Published
May 26, 2026
Updated
May 26, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, CWE-193, CWE-122, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 26, 2026CVE publishedPublication date reported by the CVE source.
  2. May 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-193Off-by-one Error
CWE-122Heap-based Buffer Overflow
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo