RHSA-2026:7224

Vulnerability from csaf_redhat - Published: 2026-04-09 04:58 - Updated: 2026-05-04 14:12
Summary
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
Severity
Important
Notes
Topic: An update for Red Hat Hardened Images RPMs is now available.
Details: This update includes the following RPMs:
Terms of Use: This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.
CVE-2026-27448

A flaw was found in pyOpenSSL. The set_tlsext_servername_callback callback function can be used to implement Server Name Indication (SNI) during the TLS handshake. When the callback raises an unhandled exception, the handshake incorrectly proceeds instead of terminating. This fail-open behavior can allow an attacker to bypass SNI-based security controls and access restricted endpoints.

5.4 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
CWE-636 - Not Failing Securely ('Failing Open')
Vendor Fix For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ https://access.redhat.com/errata/RHSA-2026:7224
Workaround To mitigate this flaw, ensure the callback provided to the set_tlsext_servername_callback function is wrapped in a try/except block. This block should explicitly return a failure code instead of allowing the exception to propagate.
CVE-2026-27459

A flaw was found in pyOpenSSL. The set_cookie_generate_callback callback function can be used to generate DTLS cookies. When the callback returns a cookie string or byte sequence longer than 256 bytes, a buffer overflow can be triggered due to a missing bounds checking before copying the data to a fixed-size buffer provided by the underlying OpenSSL library.

8.1 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE-120 - Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Vendor Fix For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ https://access.redhat.com/errata/RHSA-2026:7224
Workaround To mitigate this flaw, ensure the callback provided to the set_cookie_generate_callback function strictly limits the returned cookie string or byte sequence to under 256 bytes.
References
To clipboard 

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      "title": "pyOpenSSL: DTLS cookie callback buffer overflow"
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}


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