CVE-2026-21444

libtpms returns wrong initialization vector when certain symmetric ciphers are used

MEDIUM
5.5
CVSS Score
Published: January 2, 2026 at 07:05 PM UTC
Updated: June 17, 2026 at 10:18 AM UTC
2 products affected across 2 vendorsLibtpmsLibtpms

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

0.10.0 ≤ v < 0.10.2
v < 0.10.2
Affected range stops below 0.10.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_CONFIRMPatchVendor Advisory
Source: cverecord
https://github.com/stefanberger/libtpms/security/advisories/GHSA-7jxr-4j3g-p34f
x_refsource_MISCExploitIssue Tracking
Source: cverecord
https://github.com/stefanberger/libtpms/issues/541

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.5MEDIUMGitHub_M
Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-327CWE-330

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