FFmpeg 2.x allows remote attackers to conduct cross-origin attacks and read arbitrary files by using the concat protocol in an HTTP Live Streaming (HLS) M3U8 file, leading to an external HTTP request in which the URL string contains the first line of a local file.
Severity
CVSS 3.0
5.5 medium
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS
15% chance of exploitation in the next 30 days; higher than 96% of CVEs (scores of 2026-10-31)