Chip Alliance Core ROM up to 2.1.1 Subsystem Mode UpdateResetFlow::run toctou

Summaryinfo

A vulnerability was found in Chip Alliance Core ROM up to 2.1.1. It has been classified as problematic. The impacted element is the function UpdateResetFlow::run of the component Subsystem Mode. The manipulation leads to toctou. This vulnerability is listed as CVE-2026-11835. The attack must be carried out locally. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Chip Alliance Core ROM up to 2.1.1. This issue affects the function UpdateResetFlow::run of the component Subsystem Mode. The manipulation with an unknown input leads to a toctou vulnerability. Using CWE to declare the problem leads to CWE-367. The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state. Impacted is integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-11835 since 06/10/2026. The exploitation is known to be easy. An attack has to be approached locally. Additional levels of successful authentication are necessary for exploitation. Technical details are known, but no exploit is available.

Upgrading to version 2.1.2 eliminates this vulnerability.

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Productinfo

Vendor

• Chip Alliance

Name

• Core ROM

Version

• 2.1.0
• 2.1.1

CPE 2.3info

• 🔒
• 🔒

CPE 2.2info

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• 🔒

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