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CVE PROGRAM SOURCE RECORD6.5 Medium

CVE-2026-70368

Stunnel: stack-based out-of-bounds read/write in stunnel s_vlog via oversized log message

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".

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Mobi-Com Polska Sp. z o.o. stunnel

Default version status: unaffected

  • 5.68 to < 5.80affected

Red Hat Red Hat Enterprise Linux 10

Default version status: affected

Red Hat Red Hat Enterprise Linux 6

Default version status: unaffected

Red Hat Red Hat Enterprise Linux 7

Default version status: unaffected

Red Hat Red Hat Enterprise Linux 8

Default version status: affected

Red Hat Red Hat Enterprise Linux 9

Default version status: affected

References