CVE-2026-21444: libtpms, a library that provides software emulation of a Trusted Platform Module, has a flaw in versions 0.10.

Routine

MEDIUM 5.5UPGRADE

CVE-2026-21444 is a medium-severity flaw (CVSS 5.5) affecting libtpms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.1% (top 100%)
CISA exploited list	No
Weakness	CWE-327, CWE-330
Published	2026-01-02
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: libtpms project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-01-02 19:15 UTCPublished CVE record published
2026-06-17 10:18 UTCUpdated Record last modified

libtpms project libtpms UPGRADE

Affected: >= 0.10.0 and < 0.10.2

Fixed in: 0.10.2

Safe to downgrade to: a release before 0.10.0

1. Check installed version

apt-cache policy libtpms || rpm -q libtpms || libtpms --version

2. UPGRADE to 0.10.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade libtpms

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade libtpms

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 0.10.0 (Debian / Ubuntu)

apt-cache madison libtpms sudo apt install libtpms=<VERSION_BEFORE_0.10.0> sudo apt-mark hold libtpms

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list libtpms sudo dnf downgrade libtpms-<VERSION_BEFORE_0.10.0> sudo dnf versionlock add libtpms

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-21444?

libtpms: upgrade to 0.10.2. Exact commands for each OS are on this page.

Is CVE-2026-21444 being exploited?

CVE-2026-21444 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-21444 affect?

CVE-2026-21444 affects libtpms. Severity is medium (CVSS 5.5). 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 (init

How urgent is CVE-2026-21444?

Priority 24/100. Public exploit reference

Software pages

OpenSSL vulnerabilities

Related CVEs

CVE-2025-49133 MEDIUM 5.9 DOWNGRADE Libtpms is a library that targets the integration of TPM functionality into hypervisors, primarily into Qemu

References

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