OSV-2026-392 UNKNOWN READ in pcpp::BgpLayer::getHeaderLen

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=491687588 Crash type: UNKNOWN READ Crash state: pcpp::BgpLayer::getHeaderLen pcpp::Packet::shortenLayer pcpp::Layer::shortenLayer...