VulnerabilityAwaiting Analysis

CVE-2026-70368

A stack-based out-of-bounds read vulnerability exists in the "s_vlog" function of stunnel, when handling oversized log messages via "vsnprintf".

MEDIUM 6.5EPSS 0.35%

Does this matter?

Lower severity and a low EPSS score (0.35%). Track it; it rarely justifies an emergency change on its own.

Description

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".

CVSS 3.1: 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
EPSS: 0.35% probability · 29th percentile
CISA KEV: Not listed
Weakness: CWE-125
Source: secalert@redhat.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.