CVE-2026-73324

VLC media player copies an RTSP response line into a fixed buffer without guaranteeing termination and then treats that buffer as a C string. RtspReadLine in modules/access/rtsp/access.c calls strncpy with the full buffer length, which writes no terminator when the source line is at least as long as the destination, and rtsp_get in modules/access/rtsp/rtsp.c allocates that buffer as BUF_SIZE bytes and passes it to strdup. When a server returns a line of 4096 bytes or more, strdup measures its length past the end of the allocation and copies adjacent heap bytes until an incidental zero byte. Because the affected line is the Session header, the disclosed bytes are retained as the session identifier and sent back to the server on every subsequent request, so the operator of a hostile server reads heap memory from the client rather than inferring it. The attacker controls the line length and therefore how far the read runs. A single playlist entry naming a realrtsp URL is sufficient. The module is a build-time option, disabled in some distribution packages and enabled in the official VideoLAN builds.

Affected products

Vlc Media Player

CVSS 4.0

6.9 MEDIUM

CVSS 3.1

6.5 MEDIUM

EPSS

0.3% (26th percentile)

Weakness

CWE-170, CWE-125

NVD status

Deferred

Published

2026-09-09

No exploit for CVE-2026-73324 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.