CVE-2026-48691
FastNetMon Community Edition through 1.2.9 contains an integer overflo ...
Severity by source
Trivy's own label is CRITICAL. Rated critical by NVD. Rated lower by Ubuntu (medium).
Description
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.
Affected packages and fixed versions
| Source | Package | Fixed in |
|---|---|---|
| debian 12 | fastnetmon | no fix listed |
| debian 13 | fastnetmon | 1.2.9-0+deb13u1 |
| debian 14 | fastnetmon | 1.2.9-1 |
| echo | fastnetmon | 1.2.9-0+deb13u1 |
| rapidfort debian 12 | fastnetmon | 0:1.2.9-0+deb13u1, 0:1.2.9-1 |
| rapidfort debian 13 | fastnetmon | 0:1.2.9-0+deb13u1, 0:1.2.9-1 |
| rapidfort fedora 43 | fastnetmon | 1.2.9-2.fc43 |
| rapidfort Oracle Linux 10 | fastnetmon | no fix listed |
| rapidfort Oracle Linux 9 | fastnetmon | no fix listed |
| rapidfort ubuntu 20.04 | fastnetmon | no fix listed |
| rapidfort ubuntu 22.04 | fastnetmon | no fix listed |
| rapidfort ubuntu 24.04 | fastnetmon | no fix listed |
Show all 14 entries from 14 sources
| Source | Package | Fixed in |
|---|---|---|
| debian 12 | fastnetmon | no fix listed |
| debian 13 | fastnetmon | 1.2.9-0+deb13u1 |
| debian 14 | fastnetmon | 1.2.9-1 |
| echo | fastnetmon | 1.2.9-0+deb13u1 |
| rapidfort debian 12 | fastnetmon | 0:1.2.9-0+deb13u1, 0:1.2.9-1 |
| rapidfort debian 13 | fastnetmon | 0:1.2.9-0+deb13u1, 0:1.2.9-1 |
| rapidfort fedora 43 | fastnetmon | 1.2.9-2.fc43 |
| rapidfort Oracle Linux 10 | fastnetmon | no fix listed |
| rapidfort Oracle Linux 9 | fastnetmon | no fix listed |
| rapidfort ubuntu 20.04 | fastnetmon | no fix listed |
| rapidfort ubuntu 22.04 | fastnetmon | no fix listed |
| rapidfort ubuntu 24.04 | fastnetmon | no fix listed |
| ubuntu 24.04 | fastnetmon | no fix listed |
| ubuntu 26.04 | fastnetmon | no fix listed |
References
- https://github.com/pavel-odintsov/fastnetmon
- https://github.com/pavel-odintsov/fastnetmon/blob/master/src/bgp_protocol.hpp
- https://github.com/pavel-odintsov/fastnetmon/commit/94c66d5b100c42fb8bd10a22ca595e46895d60d0
- https://github.com/pavel-odintsov/fastnetmon/pull/1054
- https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48691-bgp-as-path-overflow
- https://ubuntu.com/security/notices/USN-8429-1
- https://www.cve.org/CVERecord?id=CVE-2026-48691