AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio or asyncio. Prior to 4.14.2, connect_tcp() and TLSStream.wrap() can validate internationalized host names after the standard library converts them with IDNA 2003 instead of IDNA 2008. When a connection to a non-ASCII domain is hijacked or redirected, an attacker can obtain a legitimate certificate for the different ASCII hostname produced by IDNA 2003 and present it to the client, causing the malicious endpoint's certificate to validate. This issue is fixed in version 4.14.2.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has a package installed that is affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:4416-1 advisory.

    - CVE-2026-63374: : TLSStream IDNA 2003 host name encoding enables potential TLS certificate spoofing     (bsc#1281476).
    - CVE-2026-64847: AnyIO process-pool workers can block indefinitely on undrained stderr (bsc#1281475).

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

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

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio
    or asyncio. Prior to 4.14.2, connect_tcp() and TLSStream.wrap() can validate internationalized host names
    after the standard library converts them with IDNA 2003 instead of IDNA 2008. When a connection to a non-
    ASCII domain is hijacked or redirected, an attacker can obtain a legitimate certificate for the different
    ASCII hostname produced by IDNA 2003 and present it to the client, causing the malicious endpoint's
    certificate to validate. This issue is fixed in version 4.14.2. (CVE-2026-63374)

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio     or asyncio. Prior to 4.14.2, connect_tcp() and TLSStream.wrap() can validate internationalized host names     after the standard library converts them with IDNA 2003 instead of IDNA 2008. When a connection to a non-     ASCII domain is hijacked or redirected, an attacker can obtain a legitimate certificate for the different     ASCII hostname produced by IDNA 2003 and present it to the client, causing the malicious endpoint's     certificate to validate. This issue is fixed in version 4.14.2. (CVE-2026-63374)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
362805	SUSE SLED15 / SLES15 Security Update : python-anyio (SUSE-SU-2026:4416-1)	Nessus	SuSE Local Security Checks	Local	critical
463520	Echo: anyio: security update to 4.14.2	Tenable Cloud Security	Echo Local Security Checks	Local	critical
463520	Echo: anyio: security update to 4.14.2	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	critical
348561	Linux Distros Unpatched Vulnerability : CVE-2026-63374	Nessus	Misc.	Local	critical

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CVE-2026-63374

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