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Fencer Vulns
medium 5.5

CVE-2026-21444 json

libtpms returns wrong initialization vector when certain symmetric ciphers are used

published 2026-01-02 10 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-0753

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 0%
public exploits
0
none known

Summary

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.

Patch / fix

  • libtpms_project libtpms 0.10.2
  • libtpms Debian 14 0.10.2-1

debian advisories DEBIAN-CVE-2026-21444

  • libtpms openSUSE Tumbleweed 0.10.2-1.1

opensuse advisories openSUSE-SU-2026:10422-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-21444 updated cvss 6.5

limtpms: libtpms: Remote data confidentiality compromise via incorrect Initialization Vector (IV) handling

  • Red Hat Enterprise Linux 8 libtpms Red Hat Enterprise Linux 9 libtpms Red Hat Enterprise Linux 10 libtpms
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
10 mo ago

Exploit prediction

0.08% chance of exploitation in the next 30 days, higher than 0% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/stefanberger/libtpms/issues/541 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products

  • stefanberger libtpms

Classification

Weakness
  • CWE-327 Use of a Broken or Risky Cryptographic Algorithm
  • CWE-330 Use of Insufficiently Random Values

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.