Security readout for executives and security teams
Plain-English summary
CVE-2026-21444 is a cryptographic flaw in libtpms 0.10.0 and 0.10.1. In common OpenSSL 3.x integrations, libtpms could return the wrong initialization vector, weakening later encryption or decryption. The primary business risk is exposure of confidential data protected through affected TPM emulation workflows.
Executive priority
Treat as a targeted confidentiality risk, not an internet-scale emergency. Patch affected libtpms deployments during the next security maintenance cycle, sooner for systems protecting regulated, sensitive, or high-value data through virtual TPM workflows.
Technical view
libtpms returned the initial IV instead of the last IV to callers when certain symmetric ciphers were used with OpenSSL 3.x. This weakens subsequent cryptographic operations. The CVSS 3.1 score is 5.5, local attack vector, low complexity, low privileges required, and high confidentiality impact. libtpms 0.10.2 fixes the issue.
Likely exposure
Exposure is likely limited to environments using libtpms versions 0.10.0 or 0.10.1, especially where integrated with OpenSSL 3.x. The vulnerability is local and requires low privileges. Systems not using affected libtpms versions are not indicated as affected by the provided sources.
Exploitation context
The source bundle does not report active exploitation, and this CVE is not marked KEV. The issue is a cryptographic weakness rather than a remote code execution flaw. Practical impact depends on whether affected symmetric cipher paths are used in sensitive TPM emulation operations.
Researcher notes
Evidence identifies CWE-327 and CWE-330. The affected range is >=0.10.0 and <0.10.2. The sources do not name the specific symmetric ciphers or provide exploitation evidence. Review the GitHub advisory, issue, and fixing commit for implementation-level details without assuming broader product impact.
Mitigation direction
- Upgrade libtpms to version 0.10.2 or later.
- Prioritize systems handling sensitive encrypted data through TPM emulation.
- If immediate upgrade is not possible, check vendor guidance; no workaround is listed.
- Track downstream packages that bundle or depend on libtpms.
Validation and detection
- Inventory libtpms versions across hosts, images, and virtualization stacks.
- Flag libtpms 0.10.0 and 0.10.1 as affected.
- Confirm whether deployments use OpenSSL 3.x integration paths.
- Verify upgraded systems report libtpms 0.10.2 or later.
- Review vendor advisories for distribution-specific package names and backports.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-327: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-330: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-21444 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N1.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/stefanberger/libtpms/security/advisories/GHSA-7jxr-4j3g-p34fCVE reference · x_refsource_CONFIRM
- https://github.com/stefanberger/libtpms/issues/541CVE reference · x_refsource_MISC
- https://github.com/stefanberger/libtpms/commit/33c9ff074cb16c1841ce7d7f33643c17c426743aCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Use of a Broken or Risky Cryptographic Algorithm
Use of a Broken or Risky Cryptographic Algorithm represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Use of Insufficiently Random Values
Use of Insufficiently Random Values represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.