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CVE-2026-11809— UpdateHub probe: uninitialized-heap out-of-bounds read of network-supplied metadata

Quick assessment

Affected
zephyrproject zephyr
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

zephyrproject zephyr是zephyrproject组织开源的一个面向物联网设备的实时操作系统。 zephyrproject zephyr 2.0.0版本至4.4.2之前版本存在安全漏洞，该漏洞源于UpdateHub OTA客户端在z_impl_updatehub_probe()函数中存在越界/未初始化内存读取问题，可能导致设备崩溃并引发拒绝服务。

CVSS 3.7 · Low EPSS 0.35% · P27

Affected Version Matrix 1

VendorProduct Version RangeStatus
zephyrproject zephyr 2.0.0< 4.4.2 affected
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I. Basic Information for CVE-2026-11809

Vulnerability Information
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Vulnerability Title
UpdateHub probe: uninitialized-heap out-of-bounds read of network-supplied metadata
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Source: CVE Program / CVE List V5
Vulnerability Type
跨界内存读
Source: CVE Program / CVE List V5
Vulnerability Title
zephyrproject zephyr 缓冲区错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
zephyrproject zephyr是zephyrproject组织开源的一个面向物联网设备的实时操作系统。 zephyrproject zephyr 2.0.0版本至4.4.2之前版本存在安全漏洞，该漏洞源于UpdateHub OTA客户端在z_impl_updatehub_probe()函数中存在越界/未初始化内存读取问题，可能导致设备崩溃并引发拒绝服务。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
zephyrproject zephyr 2.0.0 ~ 4.4.2 -

II. Public POCs for CVE-2026-11809

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III. Intelligence Information for CVE-2026-11809

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Patches & Fixes for CVE-2026-11809 (1)

Vendor Advisories for CVE-2026-11809 (1)

Same Patch Batch · zephyrproject · 2026-08-10 · 5 CVEs total

CVE-2026-8718 8.4 HIGH Out-of-bounds write in DTLS peer Connection ID getsockopt (`TLS_DTLS_PEER_CID_VALUE`) in Z
CVE-2026-11810 7.5 HIGH NULL-pointer dereference in UpdateHub OTA agent on empty inner metadata array (remote DoS)
CVE-2026-11811 3.7 LOW Socket file-descriptor leak in UpdateHub OTA client start_coap_client() leading to resourc
CVE-2026-11812 2.5 LOW UpdateHub: race condition on shared context causes out-of-bounds write and DoS

IV. Related Vulnerabilities

Same product: zephyr
Same vendor: zephyrproject
Same weakness: CWE-125

V. Comments for CVE-2026-11809

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