CVE-2026-6458AES-256-GCM Authentication Tag Does Not Cover First Ciphertext Blocks When AAD Is Empty
Updated under an hour ago ()
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It affects Caliptra Core Runtime Firmware. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 5.1 MEDIUM (v4.0, CNA)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
- Weakness (CWE)
- CWE-325
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Caliptra
- NVD analysis
- Awaiting Analysis
- Record last updated
- Jun 24, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.