{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-12634 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-12634 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-12634 is a medium-severity memory corruption vulnerability in zephyrproject zephyr, published on 19 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-12634 and fix it if it is affected.\n\nWhat it is: CVE-2026-12634 is a medium-severity memory corruption vulnerability in zephyrproject zephyr, published on 19 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-12634 in the wild and no public exploit code.\n\nAffected product: zephyrproject zephyr. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-12634/ (Markdown: https://insights.sbomify.com/CVE-2026-12634/index.md)","id":"CVE-2026-12634","markdown":"https://insights.sbomify.com/CVE-2026-12634/index.md","name":"CVE-2026-12634","record":{"aliases":["GHSA-q7c8-m2qg-385c"],"analysis":{"component_type":"operating_system","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Zephyr RTOS","requires_auth":"low_privilege","summary":"An attacker with flash access can cause a stack buffer overflow in Zephyr's settings subsystem, leading to denial of service.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"zephyr","cpe":[],"cvss":{"score":5.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H","version":"3.1"},"cwes":[{"id":"CWE-787","name":"Out-of-bounds Write"}],"description":"The NVS backend of the Zephyr settings subsystem (subsys/settings/src/settings_nvs.c) reads stored setting-name entries into fixed 74-byte stack buffers and NUL-terminates them with buf[rc] = '\\0', where rc is the return value of nvs_read(). Per its contract, nvs_read() returns the full stored entry length (wlk_ate.len), which can exceed the supplied buffer length — only MIN(len, stored_len) bytes are actually copied, but the return value may be much larger, bounded only by the NVS sector size. Three sites (settings_nvs_cache_match(), settings_nvs_load(), and settings_nvs_save()) used this value directly as the NUL index without clamping, so an oversized stored name entry causes a single \\0 byte to be written past the end of the stack buffer at an attacker-influenced offset (CWE-787).\n\nThe oversized entry cannot arise through the normal settings API, where names are bounded by SETTINGS_MAX_NAME_LEN. It requires an actor able to write the flash that backs the settings partition — a co-resident or untrusted component sharing the flash device, a malicious settings image/restore, or offline/physical flash access (a shared-flash threat model). The malformed entry is parsed when settings_load() runs at boot or subsystem init, or during settings_save().\n\nThe out-of-bounds write is a single NUL byte at an offset equal to the crafted entry length (up to the NVS sector size), so the practical impact is a crash or denial of service and limited stack corruption rather than reliable code execution. There is no confidentiality impact, and the path is not reachable from the network through the ordinary settings interface. The fix skips any entry whose nvs_read() length is greater than or equal to the buffer size before performing the NUL store.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"Out-of-bounds stack write in the settings NVS backend from over-reported nvs_read length","id":"CVE-2026-12634","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"Reliance on Reverse DNS Resolution for a Security-Critical Action in GitLab","id":"CVE-2026-12635"},"packages":[],"prev":{"headline":"Out-of-bounds write in IPv6 6LoWPAN Context Option handling via unauthenticated Router Advertisement","id":"CVE-2026-12633"},"products":["zephyr"],"published":"2026-08-19","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-20","vendors":["zephyrproject"]},"summary":"An attacker with flash access can cause a stack buffer overflow in Zephyr's settings subsystem, leading to denial of service.","url":"https://insights.sbomify.com/CVE-2026-12634/"}