OSV-2026-867 Bad-cast to std::__shared_weak_count from invalid vptr

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=520147546 Crash type: Bad-cast Crash state: Bad-cast to std::sharedweakcount from invalid vptr std::1::sharedptr::sharedptr Assimp::STEP::ReadFileHeader...

PT-2026-86157

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=520147546 Crash type: Bad-cast Crash state: Bad-cast to std:: shared weak count from invalid vptr std:: 1::shared ptr::shared ptr Assimp::STEP::ReadFileHeader...

assimp:assimp_fuzzer_ifc: Bad-cast to std::__shared_weak_count from invalid vptr in std::__1::shared_ptr<Assimp::STEP::EXPRESS::DataType const>::shared_ptr

Detailed Report: https://oss-fuzz.com/testcase?key=4579058511052800 Project: assimp Fuzzing Engine: libFuzzer Fuzz Target: assimpfuzzerifc Job Type: libfuzzerubsanassimp Platform Id: linux Crash Type: Bad-cast Crash Address: 0x5615beca3bf0 Crash State: Bad-cast to std::sharedweakcount from invali...