Red Hat Enterprise Linux 10: out-of-bounds read

Medium6.5CVE-2026-70368 · Published Aug 4, 2026 · updated Aug 6, 2026

A stack-based out-of-bounds read vulnerability exists in the "s_vlog" function of stunnel, when handling oversized log messages via "vsnprintf". A remote attacker with network access to a stunnel service can send protocol inputs that trigger a log message longer than 1024 bytes, leading to an out-of-bounds stack read and a potential crash. In certain corner cases, the same vulnerability could be used to replace a series of trailing "\n" characters with "\0".