3.7
LOW CVSS 3.1
CVE-2026-11809
UpdateHub probe: uninitialized-heap out-of-bounds read of network-supplied metadata
Description

The UpdateHub OTA client in subsys/mgmt/updatehub/updatehub.c contains an out-of-bounds / uninitialized-memory read in z_impl_updatehub_probe(). The probe response from the UpdateHub server is copied into a heap buffer (metadata) that is correctly NUL-terminated, but a second buffer (metadata_copy) is allocated with k_malloc (unzeroed) and filled with memcpy(metadata_copy, metadata, strlen(metadata)), which omits the terminating NUL. Everything after the copied content remains uninitialized heap. When the first json_obj_parse() over the array descriptor fails, the code falls back to json_obj_parse(metadata_copy, strlen(metadata_copy), ...). The strlen() call scans past the copied bytes through uninitialized heap and, if no zero byte is found before the end of the allocation, reads beyond the buffer; the resulting over-long length is then parsed as JSON. The probe payload is fully controlled by the (malicious, compromised, or — without the optional CONFIG_UPDATEHUB_DTLS — on-path) UpdateHub server, which can craft a large payload that fails the first parse to drive this path. The consequence is a read of uninitialized heap, with a worst case of an out-of-bounds read past the metadata_copy allocation that can fault and crash the update thread/device, producing a network-triggerable denial of service. The over-read data is consumed only internally to evaluate the update and is not returned to the attacker, so there is no direct information disclosure and no out-of-bounds write. The fix zeroes metadata_copy with memset before the copy, guaranteeing NUL termination and bounding strlen() within the allocation.

INFO

Published Date :

Aug. 10, 2026, 9:17 p.m.

Last Modified :

Aug. 10, 2026, 9:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-11809 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Zephyrproject zephyr
2 Zephyrproject zephyr
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 LOW e2e69745-5e70-4e92-8431-deb5529a81ad
CVSS 3.1 LOW [email protected]
CVSS 3.1 LOW MITRE-CVE
Solution
Zero initialize memory buffers before copying data to prevent uninitialized memory reads.
  • Zero the metadata_copy buffer with memset.
  • Ensure metadata_copy is NUL-terminated.
  • Apply vendor-provided patches.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-11809.

URL Resource
https://github.com/zephyrproject-rtos/zephyr/commit/69bbed5e601495a2076f25d822adbf991cae5c01
https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-6r86-hvv2-h6g4
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-11809 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-11809 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-11809 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-11809 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 10, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'zephyrproject', 'product': 'zephyr', 'versions': [{'status': 'affected', 'version': '2.0.0', 'lessThan': '4.4.2', 'versionType': 'semver'}], 'packageName': 'zephyr', 'programFiles': ['subsys/mgmt/updatehub/updatehub.c'], 'collectionURL': 'https://github.com/zephyrproject-rtos/zephyr', 'defaultStatus': 'unaffected'}]
    Added Description The UpdateHub OTA client in subsys/mgmt/updatehub/updatehub.c contains an out-of-bounds / uninitialized-memory read in z_impl_updatehub_probe(). The probe response from the UpdateHub server is copied into a heap buffer (metadata) that is correctly NUL-terminated, but a second buffer (metadata_copy) is allocated with k_malloc (unzeroed) and filled with memcpy(metadata_copy, metadata, strlen(metadata)), which omits the terminating NUL. Everything after the copied content remains uninitialized heap. When the first json_obj_parse() over the array descriptor fails, the code falls back to json_obj_parse(metadata_copy, strlen(metadata_copy), ...). The strlen() call scans past the copied bytes through uninitialized heap and, if no zero byte is found before the end of the allocation, reads beyond the buffer; the resulting over-long length is then parsed as JSON. The probe payload is fully controlled by the (malicious, compromised, or — without the optional CONFIG_UPDATEHUB_DTLS — on-path) UpdateHub server, which can craft a large payload that fails the first parse to drive this path. The consequence is a read of uninitialized heap, with a worst case of an out-of-bounds read past the metadata_copy allocation that can fault and crash the update thread/device, producing a network-triggerable denial of service. The over-read data is consumed only internally to evaluate the update and is not returned to the attacker, so there is no direct information disclosure and no out-of-bounds write. The fix zeroes metadata_copy with memset before the copy, guaranteeing NUL termination and bounding strlen() within the allocation.
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
    Added CWE CWE-125
    Added CWE CWE-908
    Added Reference https://github.com/zephyrproject-rtos/zephyr/commit/69bbed5e601495a2076f25d822adbf991cae5c01
    Added Reference https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-6r86-hvv2-h6g4
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.