CVE-2026-48690
FastNetMon Community Edition Integer Overflow Heap Corruption Vulnerability
Description
FastNetMon Community Edition through 1.2.9 contains an integer overflow vulnerability in the packet capture buffer allocation. In src/packet_storage.hpp, the allocate_buffer() function computes memory_size_in_bytes as 'buffer_size_in_packets * (max_captured_packet_size + sizeof(fastnetmon_pcap_pkthdr_t)) + sizeof(fastnetmon_pcap_file_header_t)' using unsigned int (32-bit) arithmetic. With max_captured_packet_size=1500 and sizeof(fastnetmon_pcap_pkthdr_t)=16, each packet requires approximately 1516 bytes. If buffer_size_in_packets exceeds approximately 2,832,542, the multiplication overflows, resulting in a much smaller allocation than expected. Subsequent write_packet() calls then write past the allocated buffer, causing heap corruption. The buffer_size_in_packets value is derived from the ban_details_records_count configuration parameter, which is parsed using atoi() with no overflow checking.
INFO
Published Date :
May 26, 2026, 5:16 p.m.
Last Modified :
July 24, 2026, 11:10 a.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update FastNetMon to a version later than 1.2.9.
- Apply vendor-provided patches if available.
- Avoid setting excessively large ban_details_records_count.
- Monitor memory allocation behavior.
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-2026-48690.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-48690 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-2026-48690
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-2026-48690 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-48690 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.
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CVE Translated by [email protected]
Jul. 24, 2026
Action Type Old Value New Value Added Translation Title: FastNetMon Community Edition, Description: FastNetMon Community Edition hasta la versión 1.2.9 contiene una vulnerabilidad de desbordamiento de entero en la asignación del búfer de captura de paquetes. En src/packet_storage.hpp, la función allocate_buffer() calcula memory_size_in_bytes como 'buffer_size_in_packets * (max_captured_packet_size + sizeof(fastnetmon_pcap_pkthdr_t)) + sizeof(fastnetmon_pcap_file_header_t)' utilizando aritmética de entero sin signo (32 bits). Con max_captured_packet_size=1500 y sizeof(fastnetmon_pcap_pkthdr_t)=16, cada paquete requiere aproximadamente 1516 bytes. Si buffer_size_in_packets excede aproximadamente 2.832.542, la multiplicación se desborda, lo que resulta en una asignación mucho menor de lo esperado. Las llamadas posteriores a write_packet() entonces escriben más allá del búfer asignado, causando corrupción de la pila. El valor de buffer_size_in_packets se deriva del parámetro de configuración ban_details_records_count, que se analiza utilizando atoi() sin verificación de desbordamiento. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'n/a', 'product': 'n/a', 'versions': [{'status': 'affected', 'version': 'n/a'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-48690', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-05-26T21:01:52.796415Z'} -
Initial Analysis by [email protected]
May. 27, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Added CPE Configuration OR *cpe:2.3:a:pavel-odintsov:fastnetmon:*:*:*:*:community:*:*:* versions up to (including) 1.2.9 Added Reference Type MITRE: https://github.com/pavel-odintsov/fastnetmon Types: Product Added Reference Type MITRE: https://github.com/pavel-odintsov/fastnetmon/blob/master/src/packet_storage.hpp Types: Product Added Reference Type MITRE: https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48690-packet-storage-integer-overflow Types: Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 26, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Added CWE CWE-190 Added CWE CWE-122 -
New CVE Received by [email protected]
May. 26, 2026
Action Type Old Value New Value Added Description FastNetMon Community Edition through 1.2.9 contains an integer overflow vulnerability in the packet capture buffer allocation. In src/packet_storage.hpp, the allocate_buffer() function computes memory_size_in_bytes as 'buffer_size_in_packets * (max_captured_packet_size + sizeof(fastnetmon_pcap_pkthdr_t)) + sizeof(fastnetmon_pcap_file_header_t)' using unsigned int (32-bit) arithmetic. With max_captured_packet_size=1500 and sizeof(fastnetmon_pcap_pkthdr_t)=16, each packet requires approximately 1516 bytes. If buffer_size_in_packets exceeds approximately 2,832,542, the multiplication overflows, resulting in a much smaller allocation than expected. Subsequent write_packet() calls then write past the allocated buffer, causing heap corruption. The buffer_size_in_packets value is derived from the ban_details_records_count configuration parameter, which is parsed using atoi() with no overflow checking. Added Reference https://github.com/pavel-odintsov/fastnetmon Added Reference https://github.com/pavel-odintsov/fastnetmon/blob/master/src/packet_storage.hpp Added Reference https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48690-packet-storage-integer-overflow