CVE-2026-6458
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.
Summary dbcve.org
Missing cryptographic step in Caliptra Core Firmware's aes_256_gcm_update module causes the GHASH accumulator state to not be saved after the first update call when using empty AAD, resulting in an authentication tag that excludes the first batch of ciphertext and allows undetected modifications.
Mitigation
Apply vendor-provided firmware update that corrects the GHASH state saving in the AES-256-GCM streaming API; verify cryptographic operations produce correct authentication tags after update.