stefanberger libtpms up to 0.10.1 OpenSSL 3.x risky encryption

Summaryinfo

A vulnerability described as problematic has been identified in stefanberger libtpms up to 0.10.1. Affected by this issue is some unknown functionality of the component OpenSSL 3.x. Such manipulation leads to risky encryption. This vulnerability is listed as CVE-2026-21444. The attack must be carried out locally. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in stefanberger libtpms up to 0.10.1. Affected by this issue is an unknown code block of the component OpenSSL 3.x. The manipulation with an unknown input leads to a risky encryption vulnerability. Using CWE to declare the problem leads to CWE-327. The product uses a broken or risky cryptographic algorithm or protocol. Impacted is confidentiality. CVE summarizes:

libtpms, a library that provides software emulation of a Trusted Platform Module, has a flaw in versions 0.10.0 and 0.10.1. The commonly used integration of libtpms with OpenSSL 3.x contained a vulnerability related to the returned IV (initialization vector) when certain symmetric ciphers were used. Instead of returning the last IV it returned the initial IV to the caller, thus weakening the subsequent encryption and decryption steps. The highest threat from this vulnerability is to data confidentiality. Version 0.10.2 fixes the issue. No known workarounds are available.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-21444 since 12/29/2025. The exploitation is known to be difficult. The attack needs to be approached locally. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1600.

The vulnerability scanner Nessus provides a plugin with the ID 281616 (Linux Distros Unpatched Vulnerability : CVE-2026-21444), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 0.10.2 eliminates this vulnerability. Applying the patch 33c9ff074cb16c1841ce7d7f33643c17c426743a is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (281616). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• stefanberger

Name

• libtpms

Version

• 0.10.0
• 0.10.1

License

• open-source

Website

• Product: https://github.com/stefanberger/libtpms/

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Once again VulDB remains the best source for vulnerability data.

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