CVE catalog

CVE-2026-48690

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

[CVE catalog]

Severity
High · CVSS 7.1CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Published
Source
[NVD] · [CVE record]
EPSS
0.12% · Oct 25, 2026

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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

DistributionPackageReleaseVersionStatus
Debianfastnetmonsid1.2.9-1fixed
Debianfastnetmonforky1.2.9-1fixed
Debianfastnetmontrixie1.2.9-0+deb13u1fixed
Debianfastnetmontrixie-security1.2.9-0+deb13u1fixed
Debianfastnetmonbookworm1.2.4-2+deb12u1vulnerable
Debianfastnetmonbookworm-security1.2.4-2+deb12u1vulnerable
CpefastnetmonNot reportedNot reportedvulnerable
CpefastnetmonNot reportedNot reportedunknown

Fixed-version evidence

DistributionPackageTypeReleaseFixed versionUrgencyOriginBugs
Debianfastnetmonsourcesid1.2.9-1unimportantNot reported[1138646]
Debianfastnetmonsourceforky1.2.9-1unimportantNot reported[1138646]
Debianfastnetmonsourcetrixie1.2.9-0+deb13u1not yet assignedNot reported[1138646]
Debianfastnetmonsourcebookworm(unfixed)unimportantNot reported[1138646]

[Debian bug #1138646]

OpenFactory catalog packages

[Debian 12 (Bookworm)]

  • [fastnetmon]Affected
    Details (6)

    • 1.2.4-2+deb12u1 · amd64 · bookworm

      Affected

      nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12

    • 1.2.4-2+deb12u1 · arm64 · bookworm

      Affected

      nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12

    • 1.2.8-1~bpo12+1 · amd64 · bookworm-backports

      Affected

      nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12

    • 1.2.8-1~bpo12+1 · arm64 · bookworm-backports

      Affected

      nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12

    • 1.2.4-2+deb12u1 · amd64 · bookworm-security

      Affected

      nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12

    • 1.2.4-2+deb12u1 · arm64 · bookworm-security

      Affected

      nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12

[Debian 13 (Trixie)]

  • [fastnetmon]Fixed
    Details (4)

    • 1.2.9-0+deb13u1 · amd64 · trixie

      Fixed · Fixed: 1.2.9-0+deb13u1

      nvd · fastnetmon · debian · 13

    • 1.2.9-0+deb13u1 · arm64 · trixie

      Fixed · Fixed: 1.2.9-0+deb13u1

      nvd · fastnetmon · debian · 13

    • 1.2.9-0+deb13u1 · amd64 · trixie-security

      Fixed · Fixed: 1.2.9-0+deb13u1

      nvd · fastnetmon · debian · 13

    • 1.2.9-0+deb13u1 · arm64 · trixie-security

      Fixed · Fixed: 1.2.9-0+deb13u1

      nvd · fastnetmon · debian · 13

Observed:

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]