Out-of-bounds Read Affecting stunnel package, versions <5.82-r0


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.44% (36th percentile)

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  • Snyk IDSNYK-ALPINE324-STUNNEL-20260480
  • published29 Sept 2026
  • disclosed4 Aug 2026

Introduced: 4 Aug 2026

CVE-2026-70368  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

Upgrade Alpine:3.24 stunnel to version 5.82-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream stunnel package and not the stunnel package as distributed by Alpine. See How to fix? for Alpine:3.24 relevant fixed versions and status.

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 Base Scores

version 3.1