Back to vendor advisories
Microsoft Security Response CenterCVE-2026-27448

pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback

Mariner

LowCVSS not listedLow severity
Scope

What the vendor says is affected

  • azl3 pyOpenSSL 24.2.1-1 on Azure Linux 3.0
  • cbl2 pyOpenSSL 18.0.0-8 on CBL Mariner 2.0
  • cbl2 pyOpenSSL 18.0.0-8 on CBL-Mariner 2.0

Versions the vendor lists as fixed

  • 24.2.1-2
Next step

What the vendor recommends

CBL-Mariner Releases Release Notes

Review the complete instructions on the vendor's site
Timeline

When this advisory changed

  1. Published by Microsoft Security Response Center

    The publication date reported by the vendor.

  2. Updated by Microsoft Security Response Center

    The vendor changed the advisory after it was first published.

  3. Added to SecurityAlert

    We collected the advisory from the official source.

  4. Confirmed at the source

    Our collector saw this advisory during a later source check.

Vulnerabilities

CVEs named in this advisory