Chip Alliance Core ROM/Core Firmware Subsystem Mode validate_debug_unlock_token improper authentication

Summaryinfo

A vulnerability was found in Chip Alliance Core ROM and Core Firmware and classified as very critical. The affected element is the function validate_debug_unlock_token of the component Subsystem Mode. Executing a manipulation can lead to improper authentication. This vulnerability is tracked as CVE-2026-11836. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability classified as very critical was found in Chip Alliance Core ROM and Core Firmware (the affected version is unknown). This vulnerability affects the function validate_debug_unlock_token of the component Subsystem Mode. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Insufficient verification of data authenticity in Caliptra Core ROM and Core Firmware (validate_debug_unlock_token()) in subsystem mode allows an attacker with access to the integrator's debug unlock signing service to unlock production debug on an unintended device by presenting a valid token issued for a different device sharing the same debug unlock key hash. The 384-bit challenge nonce continues to prevent replay of previously issued tokens. Practical impact is limited to loss of per-device scope enforcement within a set of devices that share the same unlock authority by design; it does not enable debug unlock on devices outside that set. This issue affects Core ROM: 2.0.0 through 2.0.2, 2.1.0 through 2.1.1; Core Firmware: 2.0.0 through 2.0.1, 2.1.0.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-11836 since 06/10/2026. The exploitation appears to be easy. The attack can be initiated remotely. Additional levels of successful authentication are required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/04/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Firmware Software

Vendor

• Chip Alliance

Name

• Core Firmware
• Core ROM

CPE 2.3info

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CPE 2.2info

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