CVE-2026-11810: memory-safety in zephyrproject zephyr
The UpdateHub firmware-update agent's probe handler (z_impl_updatehub_probe() in subsys/mgmt/updatehub/updatehub.c) parses the JSON metadata returned by the update server into a fixed two-level nested-array struct. After parsing it validates only the outer array length (objects_len != 2) and then dereferences objects[1].objects[0].objects.sha256sum via strlen() without checking that the inner object array of element [1] is non-empty. The metadata is attacker-influenceable network input: the agent fetches it over CoAP from the configured UpdateHub server during its routine OTA probe. A malicious or compromised update server (or, when DTLS is disabled, a network man-in-the-middle) can return a response whose second outer object array is empty. Because the parse target is zero-initialised, the corresponding objects[1].objects[0].objects.sha256sum pointer is NULL, and the subsequent strlen() dereferences address zero. The same defect exists in both the 'any boards' and 'some boards' metadata layouts. The resulting CPU fault is fatal under Zephyr's default error handling, halting or resetting the device, so the flaw is a remotely triggerable denial of service. Impact is limited to availability; it is a read from NULL with no out-of-bounds write, memory corruption, or information disclosure. The fix rejects metadata whose inner object array is empty before any dereference, on both layouts.
AI Analysis
Technical Summary
The UpdateHub firmware-update agent in Zephyr parses JSON metadata from an update server into a fixed two-level nested array structure. It validates only the outer array length but does not check if the inner array at index 1 is non-empty before dereferencing a sha256sum pointer via strlen(). If the inner array is empty, this pointer is NULL, causing a NULL pointer dereference and CPU fault. This flaw can be triggered remotely by a malicious or compromised update server or a network man-in-the-middle when DTLS is disabled. The fault results in a denial of service by halting or resetting the device. The vulnerability affects both 'any boards' and 'some boards' metadata layouts. The fix involves rejecting metadata with empty inner arrays prior to dereferencing.
Potential Impact
The vulnerability causes a remotely triggerable denial of service by crashing the device due to a NULL pointer dereference during JSON metadata parsing. There is no impact on confidentiality or integrity, as no memory corruption or information disclosure occurs. The device availability is affected as the CPU fault halts or resets the device under default error handling.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The described fix rejects metadata with empty inner arrays before any dereference. Until an official fix is available, ensure the update server is trusted and secure the network channel (e.g., enable DTLS) to prevent man-in-the-middle attacks.
CVE-2026-11810: memory-safety in zephyrproject zephyr
Description
The UpdateHub firmware-update agent's probe handler (z_impl_updatehub_probe() in subsys/mgmt/updatehub/updatehub.c) parses the JSON metadata returned by the update server into a fixed two-level nested-array struct. After parsing it validates only the outer array length (objects_len != 2) and then dereferences objects[1].objects[0].objects.sha256sum via strlen() without checking that the inner object array of element [1] is non-empty. The metadata is attacker-influenceable network input: the agent fetches it over CoAP from the configured UpdateHub server during its routine OTA probe. A malicious or compromised update server (or, when DTLS is disabled, a network man-in-the-middle) can return a response whose second outer object array is empty. Because the parse target is zero-initialised, the corresponding objects[1].objects[0].objects.sha256sum pointer is NULL, and the subsequent strlen() dereferences address zero. The same defect exists in both the 'any boards' and 'some boards' metadata layouts. The resulting CPU fault is fatal under Zephyr's default error handling, halting or resetting the device, so the flaw is a remotely triggerable denial of service. Impact is limited to availability; it is a read from NULL with no out-of-bounds write, memory corruption, or information disclosure. The fix rejects metadata whose inner object array is empty before any dereference, on both layouts.
CVSS v3.1
Score 7.5high
Affected software
zephyrproject
zephyr
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The UpdateHub firmware-update agent in Zephyr parses JSON metadata from an update server into a fixed two-level nested array structure. It validates only the outer array length but does not check if the inner array at index 1 is non-empty before dereferencing a sha256sum pointer via strlen(). If the inner array is empty, this pointer is NULL, causing a NULL pointer dereference and CPU fault. This flaw can be triggered remotely by a malicious or compromised update server or a network man-in-the-middle when DTLS is disabled. The fault results in a denial of service by halting or resetting the device. The vulnerability affects both 'any boards' and 'some boards' metadata layouts. The fix involves rejecting metadata with empty inner arrays prior to dereferencing.
Potential Impact
The vulnerability causes a remotely triggerable denial of service by crashing the device due to a NULL pointer dereference during JSON metadata parsing. There is no impact on confidentiality or integrity, as no memory corruption or information disclosure occurs. The device availability is affected as the CPU fault halts or resets the device under default error handling.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The described fix rejects metadata with empty inner arrays before any dereference. Until an official fix is available, ensure the update server is trusted and secure the network channel (e.g., enable DTLS) to prevent man-in-the-middle attacks.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- zephyr
- Date Reserved
- 2026-06-09T15:51:48.612Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a7a3799bf8831d5397ff9e6
Added to database: 08/10/2026, 20:42:01 UTC
Last enriched: 08/10/2026, 20:56:07 UTC
Last updated: 09/24/2026, 13:47:42 UTC
Views: 70
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