The vulnerability exists due to incorrect value length handling in X509Name field setters, where values containing NUL bytes are silently truncated, causing a divergence between the stored ASN.1 value and the value visible from Python.

The remote Fedora 43 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2026-bc62ef0a6a advisory.

    Update to pyOpenSSL 26.1.0

    This update adds support for cryptography v47 and fixes a single security issue:

    - Fixed X509Name field setters to correctly pass the value length to OpenSSL. Previously, values     containing NUL bytes would be silently truncated, causing a divergence between the stored ASN.1 value and     the value visible from Python. Credit to BudongJW for reporting the issue. CVE-2026-40475

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 44 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2026-05d463c932 advisory.

    Update to pyOpenSSL 26.1.0

    This update adds support for cryptography v47 and fixes a single security issue:

    - Fixed X509Name field setters to correctly pass the value length to OpenSSL. Previously, values     containing NUL bytes would be silently truncated, causing a divergence between the stored ASN.1 value and     the value visible from Python. Credit to BudongJW for reporting the issue. CVE-2026-40475

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 45 host has packages installed that are affected by a vulnerability as referenced in the FEDORA-2026-13a0c86ba1 advisory.

    Update python-cryptography to 47.0.0

    As a result, rust-asn1 is bumped to 0.24, and pyOpenSSL is bumped to 26.1. kryoptic is rebuilt with a     patch to support asn1 0.24.

    pyOpenSSL 26.1 contains a fix for CVE-2026-40475

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version
    26.0.0, if a user provided callback to `set_tlsext_servername_callback` raised an unhandled exception,
    this would result in a connection being accepted. If a user was relying on this callback for any security-
    sensitive behavior, this could allow bypassing it. Starting in version 26.0.0, unhandled exceptions now
    result in rejecting the connection. (CVE-2026-27448)

  - pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 22.0.0 and prior to version
    26.0.0, if a user provided callback to `set_cookie_generate_callback` returned a cookie value greater than
    256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0.0, cookie values
    that are too long are now rejected. (CVE-2026-27459)

ID	Name	Product	Family	Severity
312667	Fedora 43 : pyOpenSSL (2026-bc62ef0a6a)	Nessus	Fedora Local Security Checks	critical
312319	Fedora 44 : pyOpenSSL (2026-05d463c932)	Nessus	Fedora Local Security Checks	critical
311099	Fedora 45 : kryoptic / pyOpenSSL / python-cryptography / rust-asn1 / etc (2026-13a0c86ba1)	Nessus	Fedora Local Security Checks	critical
440908	Alpine: multiple py3-openssl packages: security update to 26.1.0-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	critical
440908	Alpine: multiple py3-openssl packages: security update to 26.1.0-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	critical

Detections

Analytics

CVE-2026-40475

critical

Tenable Plugins

critical

critical

critical

critical

critical