# CVE-2026-21444: libtpms returns wrong initialization vector when certain symmetric ciphers are used

> libtpms returns the initial IV instead of the last IV for certain symmetric ciphers, weakening encryption and compromising data confidentiality.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Jan 2026
- **Updated:** 5 Jan 2026
- **Also known as:** DEBIAN-CVE-2026-21444, GHSA-7jxr-4j3g-p34f, openSUSE-SU-2026:10422-1

## What is CVE-2026-21444?

CVE-2026-21444 is a medium-severity vulnerability in stefanberger libtpms, published on 2 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-330 (Use of Insufficiently Random Values), CWE-327 (Use of a Broken or Risky Cryptographic Algorithm)

## Which versions are affected by CVE-2026-21444?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `libtpms` | openSUSE:Tumbleweed | All versions | 0.10.2-1.1 |

Products: Libtpms Project Libtpms.

## How do I fix CVE-2026-21444?

Upgrade to a fixed version.

## Is CVE-2026-21444 being exploited?

There is no known exploitation of CVE-2026-21444 in the wild and no public exploit code.

## Other vulnerabilities in stefanberger libtpms

- [CVE-2025-49133](https://insights.sbomify.com/CVE-2025-49133/): Libtpms contains a possible out-of-bound access and abort due to HMAC signing issue (medium 5.9)
- [CVE-2021-3569](https://insights.sbomify.com/CVE-2021-3569/): Memory corruption in libtpms (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21444 and fix it if it is affected.

What it is: CVE-2026-21444 is a medium-severity vulnerability in stefanberger libtpms, published on 2 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-21444 in the wild and no public exploit code.

Affected product: stefanberger libtpms. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-21444/ (Markdown: https://insights.sbomify.com/CVE-2026-21444/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21444
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21444
- OSV: https://osv.dev/vulnerability/CVE-2026-21444

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-21444/
Summaries are generated and may contain mistakes; the official description above is the record.