CVE-2026-48691: n/a
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.
AI Analysis
Technical Summary
CVE-2026-48691 is an integer overflow vulnerability in FastNetMon Community Edition (up to version 1.2.9) within the BGP AS_PATH attribute encoder. The function IPv4UnicastAnnounce::get_attributes() calculates the attribute length using a uint8_t field, which cannot correctly represent lengths exceeding 255 bytes. When the AS_PATH contains more than 63 ASNs, the length value truncates, leading to a heap buffer overflow due to buffer sizing based on the truncated length but writing the full data. A similar truncation occurs with the path_segment_length field, also a uint8_t, when more than 255 ASNs are present. This vulnerability could lead to memory corruption.
Potential Impact
The vulnerability causes a heap buffer overflow in the BGP AS_PATH attribute encoder of FastNetMon Community Edition. This memory corruption could potentially be exploited to cause application crashes or enable arbitrary code execution depending on the context and attacker capabilities. However, no known exploits are reported in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or workaround information is currently available. Users should monitor vendor communications for patches addressing this integer overflow and buffer overflow issue.
CVE-2026-48691: n/a
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-48691 is an integer overflow vulnerability in FastNetMon Community Edition (up to version 1.2.9) within the BGP AS_PATH attribute encoder. The function IPv4UnicastAnnounce::get_attributes() calculates the attribute length using a uint8_t field, which cannot correctly represent lengths exceeding 255 bytes. When the AS_PATH contains more than 63 ASNs, the length value truncates, leading to a heap buffer overflow due to buffer sizing based on the truncated length but writing the full data. A similar truncation occurs with the path_segment_length field, also a uint8_t, when more than 255 ASNs are present. This vulnerability could lead to memory corruption.
Potential Impact
The vulnerability causes a heap buffer overflow in the BGP AS_PATH attribute encoder of FastNetMon Community Edition. This memory corruption could potentially be exploited to cause application crashes or enable arbitrary code execution depending on the context and attacker capabilities. However, no known exploits are reported in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or workaround information is currently available. Users should monitor vendor communications for patches addressing this integer overflow and buffer overflow issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-05-22T00:00:00.000Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a15d231891d628fdc604cc8
Added to database: 5/26/2026, 5:02:41 PM
Last enriched: 5/26/2026, 5:19:43 PM
Last updated: 5/26/2026, 9:53:25 PM
Views: 2
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