CVE-2026-48686: n/a
FastNetMon Community Edition up to version 1. 2. 9 contains a stack-based buffer overflow vulnerability in its BGP NLRI decoder. The vulnerability arises because the prefix_bit_length value from a BGP packet is not validated to ensure it is within the valid range for IPv4 prefixes (<= 32). This leads to a buffer overflow when copying data into a fixed-size stack variable, potentially allowing arbitrary code execution. Additionally, an invalid prefix_bit_length can cause undefined behavior due to improper bit shifting. No patch or official remediation guidance is currently available, and no known exploits have been reported in the wild.
AI Analysis
Technical Summary
CVE-2026-48686 is a stack-based buffer overflow vulnerability in FastNetMon Community Edition (through version 1.2.9) within the BGP NLRI decoder. The function decode_bgp_subnet_encoding_ipv4_raw() reads the prefix_bit_length directly from the BGP packet without validating that it is less than or equal to 32 for IPv4 prefixes. This unchecked value is used to calculate the number of bytes to copy into a 4-byte stack buffer via memcpy(), resulting in an overflow of up to 28 bytes. This flaw can lead to arbitrary code execution. Furthermore, the invalid prefix_bit_length is used in a bit-shift operation causing undefined behavior. The vulnerability was published on May 26, 2026, but no CVSS score or patch information is available.
Potential Impact
The vulnerability allows an attacker to cause a stack buffer overflow by sending a crafted BGP packet with an invalid prefix_bit_length. This overflow can lead to arbitrary code execution on the affected system. Additionally, undefined behavior caused by improper bit shifting may lead to crashes or other unpredictable outcomes. There are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should consider restricting or filtering BGP traffic from untrusted sources to reduce exposure to malicious packets exploiting this vulnerability.
CVE-2026-48686: n/a
Description
FastNetMon Community Edition up to version 1. 2. 9 contains a stack-based buffer overflow vulnerability in its BGP NLRI decoder. The vulnerability arises because the prefix_bit_length value from a BGP packet is not validated to ensure it is within the valid range for IPv4 prefixes (<= 32). This leads to a buffer overflow when copying data into a fixed-size stack variable, potentially allowing arbitrary code execution. Additionally, an invalid prefix_bit_length can cause undefined behavior due to improper bit shifting. No patch or official remediation guidance is currently available, and no known exploits have been reported in the wild.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-48686 is a stack-based buffer overflow vulnerability in FastNetMon Community Edition (through version 1.2.9) within the BGP NLRI decoder. The function decode_bgp_subnet_encoding_ipv4_raw() reads the prefix_bit_length directly from the BGP packet without validating that it is less than or equal to 32 for IPv4 prefixes. This unchecked value is used to calculate the number of bytes to copy into a 4-byte stack buffer via memcpy(), resulting in an overflow of up to 28 bytes. This flaw can lead to arbitrary code execution. Furthermore, the invalid prefix_bit_length is used in a bit-shift operation causing undefined behavior. The vulnerability was published on May 26, 2026, but no CVSS score or patch information is available.
Potential Impact
The vulnerability allows an attacker to cause a stack buffer overflow by sending a crafted BGP packet with an invalid prefix_bit_length. This overflow can lead to arbitrary code execution on the affected system. Additionally, undefined behavior caused by improper bit shifting may lead to crashes or other unpredictable outcomes. There are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should consider restricting or filtering BGP traffic from untrusted sources to reduce exposure to malicious packets exploiting this vulnerability.
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: 6a15c08c891d628fdc571230
Added to database: 5/26/2026, 3:47:24 PM
Last enriched: 5/26/2026, 4:02:47 PM
Last updated: 5/26/2026, 5:01:28 PM
Views: 3
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