{"affected":[{"defaultStatus":"unaffected","ecosystem":"https://github.com/zephyrproject-rtos/zephyr","packageName":"zephyr","product":"zephyr","source":"CNA: zephyr","vendor":"zephyrproject","versions":[{"lessThan":"4.3.2","status":"affected","version":"2.0.0","versionType":"semver"},{"lessThan":"4.4.2","status":"affected","version":"4.4.0","versionType":"semver"}]}],"cveId":"CVE-2026-11809","cwes":["CWE-125","CWE-908"],"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.\n\nWhen 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.\n\nThe 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.\n\nThe fix zeroes metadata_copy with memset before the copy, guaranteeing NUL termination and bounding strlen() within the allocation.","epss":{"date":"2026-11-03","percentile":0.29072,"score":0.00353},"exploits":[],"kev":null,"metrics":[{"score":3.7,"severity":"low","source":"CNA: zephyr","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"},{"score":3.7,"severity":"low","source":"NVD: vulnerabilities@zephyrproject.org","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"}],"modifiedAt":1793769509980,"publishedAt":1786394193022,"references":[{"source":"CNA: zephyr","tags":["patch"],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/69bbed5e601495a2076f25d822adbf991cae5c01"},{"source":"CNA: zephyr","tags":[],"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-6r86-hvv2-h6g4"},{"source":"vulnerabilities@zephyrproject.org","tags":[],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/69bbed5e601495a2076f25d822adbf991cae5c01"},{"source":"vulnerabilities@zephyrproject.org","tags":[],"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-6r86-hvv2-h6g4"}],"remediation":[{"kind":"fix","source":"CNA: zephyr","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/zephyrproject-rtos/zephyr/commit/69bbed5e601495a2076f25d822adbf991cae5c01"}],"revision":"b08fcb61dc5fa599fd7756585c1bdac29912ace18cf635b374be4dbeff3ac717","sources":[{"modifiedAt":1793768356610,"name":"CNA: zephyr","retrievedAt":1793768965431,"url":"https://www.cve.org/CVERecord?id=CVE-2026-11809"},{"modifiedAt":1793769509980,"name":"NVD","retrievedAt":1793772952971,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-11809"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793768988575,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-11809"}],"ssvc":{"assessedAt":1786458514717,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"UpdateHub probe: uninitialized-heap out-of-bounds read of network-supplied metadata","updatedAt":1793772952971}