OSV-2026-308 Heap-buffer-overflow in vcardstructured_new_from_string

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=486715154 Crash type: Heap-buffer-overflow WRITE 8 Crash state: vcardstructurednewfromstring vcardparametersetvaluefromstring parsevcard...