CVE-2026-48690: FastNetMon Community Edition through 1.2.9 contains an integer overflow vulnerability in the packet capture bu

Q: How do I fix CVE-2026-48690?

fastnetmon: upgrade to newer than 1.2.9. Exact commands for each OS are on this page.

Q: Is CVE-2026-48690 being exploited?

CVE-2026-48690 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-48690 affect?

CVE-2026-48690 affects fastnetmon. Severity is high (CVSS 7.1). 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_packet

Routine

HIGH 7.1UPGRADE

CVE-2026-48690 is a high-severity flaw (CVSS 7.1) affecting fastnetmon. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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_p

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.1 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.1% (top 98%)
CISA exploited list	No
Weakness	CWE-122, CWE-190
Published	2026-05-26
Last modified	2026-07-24

Publisher (CNA): MITRE · Vendor: pavel-odintsov

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-26 17:16 UTCPublished CVE record published
2026-07-24 11:10 UTCUpdated Record last modified

pavel-odintsov fastnetmon UPGRADE

Affected: <= 1.2.9

Fixed in: newer than 1.2.9

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy fastnetmon || rpm -q fastnetmon || fastnetmon --version

2. UPGRADE to newer than 1.2.9 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade fastnetmon

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade fastnetmon

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-48690?

fastnetmon: upgrade to newer than 1.2.9. Exact commands for each OS are on this page.

Is CVE-2026-48690 being exploited?

CVE-2026-48690 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-48690 affect?

CVE-2026-48690 affects fastnetmon. Severity is high (CVSS 7.1). 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_packet

How urgent is CVE-2026-48690?

Priority 25/100. High severity

Related CVEs

CVE-2026-48689 CRITICAL 9.8 UPGRADE FastNetMon Community Edition through 1.2.9 contains an off-by-one heap-based buffer overflow in the dynamic_bi
CVE-2026-48686 CRITICAL 9.8 UPGRADE FastNetMon Community Edition through 1.2.9 contains a stack-based buffer overflow in the BGP NLRI (Network Lay
CVE-2026-48691 CRITICAL 9.8 UPGRADE FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder
CVE-2026-48688 HIGH 7.5 UPGRADE FastNetMon Community Edition through 1.2.9 contains multiple out-of-bounds reads in the BGP MP_REACH_NLRI IPv6
CVE-2026-48684 MEDIUM 6.5 UPGRADE FastNetMon Community Edition through 1.2.9 contains an out-of-bounds read in the NetFlow v9 options template p

References

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