CVE-2026-70368: Stunnel: stack-based out-of-bounds read/write in stunnel s_vlog via oversized log message
CSIRTS triage
- What
- A stack-based buffer overflow in Stunnel's logging function allows out-of-bounds read/write when processing oversized log messages.
- Who is affected
- Stunnel installations with custom logging enabled or exposed to oversized log inputs.
- Urgency
- Medium severity with CVSS 6.5; memory corruption can lead to code execution or denial of service.
- Action
- Upgrade Stunnel to the patched version or limit log message size via configuration.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70368
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-703680.35% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 28% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-70368 | coverage & exploitation status | NVD · CVE.org |
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