CVE catalog
CVE-2026-48691
FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder. In src/bgp_protocol.hpp, the IPv4UnicastAnnounce::get_attributes() function computes attri
- Severity
- Critical · CVSS 9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.31% · Oct 25, 2026
FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder. In src/bgp_protocol.hpp, the IPv4UnicastAnnounce::get_attributes() function computes attribute_length as 'sizeof(bgp_as_path_segment_element_t) + this->as_path_asns.size() * sizeof(uint32_t)' and stores it in a uint8_t field (line 600-605). Since uint8_t can only hold values 0-255, an AS_PATH containing more than 63 ASNs (2 + 64*4 = 258 > 255) causes silent truncation. The truncated length is used for buffer sizing, while the actual data written is the full untruncated amount, resulting in a heap buffer overflow. Similarly, the path_segment_length field at line 621 is also uint8_t, truncating with more than 255 ASNs.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | fastnetmon | sid | 1.2.9-1 | fixed |
| Debian | fastnetmon | forky | 1.2.9-1 | fixed |
| Debian | fastnetmon | trixie | 1.2.9-0+deb13u1 | fixed |
| Debian | fastnetmon | trixie-security | 1.2.9-0+deb13u1 | fixed |
| Debian | fastnetmon | bookworm | 1.2.4-2+deb12u1 | vulnerable |
| Debian | fastnetmon | bookworm-security | 1.2.4-2+deb12u1 | vulnerable |
| Cpe | fastnetmon | Not reported | Not reported | vulnerable |
| Cpe | fastnetmon | Not reported | Not reported | unknown |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | fastnetmon | source | sid | 1.2.9-1 | unimportant | Not reported | [1138646] |
| Debian | fastnetmon | source | forky | 1.2.9-1 | unimportant | Not reported | [1138646] |
| Debian | fastnetmon | source | trixie | 1.2.9-0+deb13u1 | not yet assigned | Not reported | [1138646] |
| Debian | fastnetmon | source | bookworm | (unfixed) | unimportant | Not reported | [1138646] |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [fastnetmon]Affected
Details (6)
1.2.4-2+deb12u1· amd64 · bookwormAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
1.2.4-2+deb12u1· arm64 · bookwormAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
1.2.8-1~bpo12+1· amd64 · bookworm-backportsAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
1.2.8-1~bpo12+1· arm64 · bookworm-backportsAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
1.2.4-2+deb12u1· amd64 · bookworm-securityAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
1.2.4-2+deb12u1· arm64 · bookworm-securityAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
[Debian 13 (Trixie)]
- [fastnetmon]Fixed
Details (4)
1.2.9-0+deb13u1· amd64 · trixieFixed · Fixed:
1.2.9-0+deb13u1nvd · fastnetmon · debian · 13
1.2.9-0+deb13u1· arm64 · trixieFixed · Fixed:
1.2.9-0+deb13u1nvd · fastnetmon · debian · 13
1.2.9-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.2.9-0+deb13u1nvd · fastnetmon · debian · 13
1.2.9-0+deb13u1· arm64 · trixie-securityFixed · Fixed:
1.2.9-0+deb13u1nvd · fastnetmon · debian · 13
Observed:
References
- [https://nvd.nist.gov/vuln/detail/CVE-2026-48691]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-48691]
- [https://security-tracker.debian.org/tracker/CVE-2026-48691]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48691.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]