CVE-2026-11836
Received Received - Intake

Insufficient Token Validation in Caliptra Core

Vulnerability report for CVE-2026-11836, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-08-04

Last updated on: 2026-08-04

Assigner: b01ddd03-5ef6-483b-b2c5-acba77f1a554

Description

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.

CVSS Scores

EPSS Scores

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Meta Information

Published
2026-08-04
Last Modified
2026-08-04
Generated
2026-08-04
AI Q&A
2026-08-04
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
caliptra core_rom From 2.0.0 (inc) to 2.0.2 (inc)
caliptra core_firmware From 2.0.0 (inc) to 2.0.1 (inc)
caliptra core_firmware 2.1.0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-345 The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

Attack-Flow Graph

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Executive Summary

This vulnerability involves insufficient verification of data authenticity in Caliptra Core ROM and Core Firmware. An attacker with access to the debug unlock signing service could unlock production debug on an unintended device by using a valid token meant for a different device that shares the same debug unlock key hash. The 384-bit challenge nonce prevents replay of old tokens.

Detection Guidance

Detection requires checking Caliptra Core ROM and Core Firmware versions. Verify if your system runs affected versions (ROM 2.0.0-2.0.2, 2.1.0-2.1.1 or Firmware 2.0.0-2.0.1, 2.1.0). Inspect debug unlock token handling logs for improper validation events.

Impact Analysis

The impact is limited to devices sharing the same unlock authority. It does not enable debug unlock on devices outside that set. The main risk is loss of per-device scope enforcement within affected devices.

Mitigation Strategies

Update Caliptra Core ROM and Core Firmware to versions beyond the affected range. Ensure debug unlock tokens are unique per device and not shared across multiple devices. Review and restrict access to the debug unlock signing service.

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