{"id":"CVE-2026-18418","summary":"Out-of-bounds read when the zbus proxy agent IPC backend logs a rejected peer frame's channel name","details":"The zbus proxy agent IPC backend in subsys/zbus/proxy_agent/zbus_proxy_agent_ipc.c logged the channel name of a rejected inter-domain frame with a plain %s conversion. The frame type struct zbus_proxy_msg carries a fixed-size channel_name[] array as its last member, and nothing in the transport guarantees the array is NUL-terminated. The only code that verifies termination is zbus_proxy_agent_receive_cb() in subsys/zbus/proxy_agent/zbus_proxy_agent.c, which rejects the frame in precisely those cases — so the warning printed a non-terminated buffer exactly on the error paths where the name had been found invalid (or, for an invalid message_size, had not been inspected at all).\n\nAny peer domain able to place a frame of sizeof(struct zbus_proxy_msg) bytes on the bound ipc_service endpoint can trigger it, by sending a frame with an out-of-range message_size or with channel_name[] containing no NUL byte. Reaching the code requires CONFIG_ZBUS_PROXY_AGENT_IPC and logging built at warning level or above (the default), and requires control over the firmware of the peer domain — typically a second core on the same SoC.\n\nThe resulting strlen() inside the log packager walks past the end of the frame object until it finds a zero byte. With the icmsg backend the frame lives in a stack buffer of the IPC work-queue thread, so bytes of that thread's stack are rendered into the log message; with the rpmsg backends the scan continues through the shared vring memory. Impact is bounded to disclosure of a small amount of adjacent memory into the receiving domain's log sink, plus a possible fatal fault if the scan leaves a mapped region; the log packager's own -ENOSPC bound prevents the overrun from becoming a write. The fix bounds the conversion with %.*s and MIN(msg-\u003echannel_name_len, sizeof(msg-\u003echannel_name)).","aliases":["GHSA-48w8-fjhj-r9w8"],"modified":"2026-10-12T02:41:03.100736Z","published":"2026-10-11T17:15:00.221Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/18xxx/CVE-2026-18418.json","cna_assigner":"zephyr","cwe_ids":["CWE-125"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/18xxx/CVE-2026-18418.json"},{"type":"PACKAGE","url":"https://github.com/zephyrproject-rtos/zephyr"},{"type":"FIX","url":"https://github.com/zephyrproject-rtos/zephyr/commit/fc065f79a568a6c6cc14b89795bd60e5eabd6f02"},{"type":"ADVISORY","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-48w8-fjhj-r9w8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-18418"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/zephyrproject-rtos/zephyr","events":[{"introduced":"684c9e8f32e4373a21098559f748f06915f950c9"},{"fixed":"dccb09599635bdff17633fa7e9dab014b91dce90"}],"database_specific":{"extracted_events":[{"introduced":"4.4.0"},{"fixed":"4.4.2"}],"source":"AFFECTED_FIELD"}}],"versions":["v4.4.2-rc1","v4.4.1","v4.4.1-rc1","v4.4.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-18418.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:L"}]}