CVE-2026-11835: Caliptra Core Rom

Medium severity, CVSS 5.7. EPSS: 0.1% chance of exploitation in the next 30 days.

Time-of-check time-of-use (TOCTOU) vulnerability combined with missing input validation in Caliptra Core ROM (UpdateResetFlow::run()) in subsystem mode allows a compromised local attacker to silently bypass secure boot by supplying an AXI staging address that is not validated against the strap-configured SS_EXTERNAL_STAGING_AREA_BASE_ADDR, enabling firmware to be modified between verification and loading into ICCM. Attestation continues to report the originally verified image digest, masking the compromise. Exploitation requires a compromised MCU firmware with AXI manager access to unprotected SRAM reachable by Caliptra. This issue affects Core ROM: 2.1.0 through 2.1.1.

Affected products

• Caliptra Core Rom: from 2.1.0, up to and including 2.1.1

Published 2026-08-04. Last modified 2026-09-03.