Description
Missing cryptographic step in Caliptra Core Firmware (aes_256_gcm_update module) results in an incorrect GCM authentication tag. When the streaming AES-256-GCM API is used with empty AAD, the hardware GHASH accumulator state is not saved after the first update call, causing the final tag to exclude the first batch of processed ciphertext. Ciphertext produced by that call may be modified without the tag reflecting the change.

This issue affects Core Runtime Firmware: from 2.0.0 through 2.0.1, 2.1.0.
Published: 2026-06-23
Score: 5.1 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

No analysis available yet.

Remediation

No remediation available yet.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Wed, 24 Jun 2026 00:15:00 +0000

Type Values Removed Values Added
Description Missing cryptographic step in Caliptra Core Firmware (aes_256_gcm_update module) results in an incorrect GCM authentication tag. When the streaming AES-256-GCM API is used with empty AAD, the hardware GHASH accumulator state is not saved after the first update call, causing the final tag to exclude the first batch of processed ciphertext. Ciphertext produced by that call may be modified without the tag reflecting the change. This issue affects Core Runtime Firmware: from 2.0.0 through 2.0.1, 2.1.0.
Title AES-256-GCM Authentication Tag Does Not Cover First Ciphertext Blocks When AAD Is Empty
Weaknesses CWE-325
References
Metrics cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N'}

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: Caliptra

Published:

Updated: 2026-06-23T23:49:44.591Z

Reserved: 2026-04-16T21:11:47.086Z

Link: CVE-2026-6458

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-325

    Missing Cryptographic Step