CVE-2026-48685 Memory corruption in n/a
FastNetMon Community Edition suffers from out-of-bounds memory access due to incorrect BGP attribute parsing, potentially allowing attackers to cause denial of service or execute arbitrary code.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-48685?
CVE-2026-48685 is a medium-severity memory corruption vulnerability in n/a, published on 26 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-130
Which versions are affected by CVE-2026-48685?
It affects 1 product.
Products include Pavel-Odintsov Fastnetmon.
How do I fix CVE-2026-48685?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-48685 being exploited?
There is no known exploitation of CVE-2026-48685 in the wild and no public exploit code.
Other vulnerabilities in n/a
Sources
Also known as DEBIAN-CVE-2026-48685, GHSA-4h2g-xxvj-v3w5, UBUNTU-CVE-2026-48685.