The vulnerability resides in the BGPHeader.DecodeFromBytes function within GoBGP’s packet handling module. The function fails to enforce proper access controls on BGP header data received from remote peers, allowing a malicious actor to manipulate the parsing logic. Because the BGP header dictates how routing updates are interpreted, this flaw can lead to unauthorized manipulation of routing information or potential disclosure of state. The description indicates remote exploitation is possible, though the attack requires high complexity and is considered difficult to execute.

The flaw affects the GoBGP routing software produced by osrg, specifically any installation running version 4.3.0 or earlier. The affected component is the BGP Header Handler, which is part of the GoBGP core packet library. No further version granularity is listed in the CNA data beyond the 4.3.0 cutoff.

The CVSS score of 6.3 places the vulnerability in the moderate range, while the EPSS score of less than 1 % indicates a low probability of observed exploitation. The flaw is not currently listed in CISA’s KEV catalog, so it is not known to have been widely exploited in the wild. Attackers would need to establish a BGP session with a vulnerable GoBGP instance and craft a malicious header, making the exploitation path complex and demanding expertise in BGP protocol internals. In the absence of an active exploitation tool, the overall risk to deployed systems remains moderate but actionable.