CVE-2026-28799 PJSIP: Heap use-after-free in PJSIP presence subscription termination handler

PJSIP is a free and open source multimedia communication library written in C. Prior to version 2.17, a heap use-after-free vulnerability exists in PJSIP's event subscription framework evsub.c that is triggered during presence unsubscription SUBSCRIBE with Expires=0. This issue has been patched i...