CVE-2026-70368 — Stunnel: stack-based out-of-bounds read/write in stunnel s_vlog via oversized log message
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 a…
Published: 2026-08-04 · CVSS: 6.5 · CVSS 3.1
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".
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7