{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-15923 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-15923 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-15923 is a medium-severity denial of service vulnerability in zephyrproject zephyr, published on 14 Sep 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-2026-15923 and fix it if it is affected.\n\nWhat it is: CVE-2026-15923 is a medium-severity denial of service vulnerability in zephyrproject zephyr, published on 14 Sep 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-2026-15923 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-2026-15923/ (Markdown: https://insights.sbomify.com/CVE-2026-15923/index.md)","id":"CVE-2026-15923","markdown":"https://insights.sbomify.com/CVE-2026-15923/index.md","name":"CVE-2026-15923","record":{"aliases":["GHSA-4pvm-wrcp-jjf5"],"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":"none","summary":"A malicious SDIO card can cause an infinite loop and permanent denial of service in Zephyr RTOS by reporting a zero block size.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"zephyr","cpe":[],"cvss":{"score":4.6,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-835","name":"Loop with Unreachable Exit Condition"}],"description":"The Zephyr SDIO subsystem function sdio_io_rw_extended_helper() in subsys/sd/sdio.c finishes transfers with a byte-I/O loop that uses size = MIN(remaining, func-\u003ecis.max_blk_size) as the per-iteration step. The value func-\u003ecis.max_blk_size is decoded directly from the SDIO card's CIS FUNCE tuple in sdio_decode_cis() and is not validated. When a card reports a maximum block size of zero, size is always 0, remaining never decreases, and the loop spins forever.\n\nThe loop is reached from the public SDIO client API used by drivers, including sdio_read_fifo(), sdio_write_fifo(), and the incrementing register read/write helpers, each of which enters the loop while holding the per-card mutex func-\u003ecard-\u003elock. A card advertising max_blk_size == 0 therefore hangs the calling thread permanently on its first non-block-aligned transfer and never releases the mutex, denying service to the SDIO peripheral (and any subsystem such as Wi-Fi that depends on it) until the device is reset.\n\nThe malicious value must come from the SDIO card itself, so the defect is exploitable where a removable SDIO/combo card slot lets an attacker insert a crafted or malfunctioning card (a physical attack vector); on boards with a soldered SDIO peripheral it is not attacker-influenceable. There is no memory-safety, confidentiality, or integrity impact — only a permanent availability loss. The fix returns -EIO when func-\u003ecis.max_blk_size is zero, before the loop is entered.","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":"Infinite loop denial of service in Zephyr SDIO byte-I/O from a card-supplied zero max_blk_size","id":"CVE-2026-15923","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"Use-after-free / double-free from unsynchronized concurrent access to the TLS client session cache in Zephyr sockets","id":"CVE-2026-15924"},"packages":[],"prev":{"headline":"nvm path traversal via a malicious mirror's LTS codename writes outside the alias directory","id":"CVE-2026-15921"},"products":["zephyr"],"published":"2026-09-14","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":"2026-09-14","vendors":["zephyrproject"]},"summary":"A malicious SDIO card can cause an infinite loop and permanent denial of service in Zephyr RTOS by reporting a zero block size.","url":"https://insights.sbomify.com/CVE-2026-15923/"}