CVE catalog

CVE-2026-48685

FastNetMon Community Edition through 1.2.9 has out-of-bounds memory access because it incorrectly parses BGP path attributes with the extended length flag set. In src/bgp_protocol.hpp, the parse_raw_b

[CVE catalog]

Severity
Medium · CVSS 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Published
Source
[NVD] · [CVE record]
EPSS
0.29% · Oct 25, 2026

FastNetMon Community Edition through 1.2.9 has out-of-bounds memory access because it incorrectly parses BGP path attributes with the extended length flag set. In src/bgp_protocol.hpp, the parse_raw_bgp_attribute() function correctly identifies when extended_length_bit is set and sets length_of_length_field to 2, but then reads only a single byte for the attribute value length (attribute_value_length = value[2] at line 173). Per RFC 4271 Section 4.3, when the Extended Length bit is set, the Attribute Length field is two octets and the value should be read as a 16-bit big-endian integer from value[2] and value[3]. As a result, any attribute longer than 255 bytes has its length silently truncated to the low byte (e.g., 300 bytes = 0x012C is read as 0x2C = 44 bytes). The remaining 256 bytes are then misinterpreted as subsequent attributes, causing cascading parse failures and potential out-of-bounds memory access.

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]