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.