CVE-2026-6458

MEDIUM

Caliptra Core Runtime Firmware - Incorrect AES-256-GCM Authentication Tag

Title source: manual

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.

References (1)

Core 1

Core References

https://github.com/chipsalliance/caliptra-sw/security/advisories/GHSA-834g-h5x6-2hqr

Scores

CVSS v4 5.1

EPSS 0.0013

EPSS Percentile 2.8%

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-325

Status published

Products (4)

Caliptra/Core Runtime Firmware 2.0.0 - 2.0.1

Caliptra/Core Runtime Firmware 2.0.2

Caliptra/Core Runtime Firmware 2.1.0

Caliptra/Core Runtime Firmware 2.1.1

Published Jun 24, 2026

Tracked Since Jun 24, 2026