PJSIP is a free and open source multimedia communication library written in C. Versions 2.12 and prior contain a stack buffer overflow vulnerability that affects PJSUA2 users or users that call the API pjmedia_sdp_print(), pjmedia_sdp_media_print(). Applications that do not use PJSUA2 and do not directly call pjmedia_sdp_print() or pjmedia_sdp_media_print() should not be affected. A patch is available on the master branch of the pjsip/pjproject GitHub repository. There are currently no known workarounds.