{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-10657","assignerOrgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","state":"PUBLISHED","assignerShortName":"zephyr","dateReserved":"2026-06-02T15:24:32.170Z","datePublished":"2026-07-05T22:23:37.533Z","dateUpdated":"2026-07-06T18:51:56.291Z"},"containers":{"cna":{"providerMetadata":{"orgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","shortName":"zephyr","dateUpdated":"2026-07-05T22:23:37.533Z"},"title":"Out-of-bounds read in Zephyr DNS resolver mDNS suffix check (memcmp past string NUL)","descriptions":[{"lang":"en","value":"Zephyr's DNS resolver detects mDNS (.local) queries in dns_resolve_name_internal() (subsys/net/lib/dns/resolve.c) with memcmp(strrchr(query, '.'), \".local\", 7), which always reads a fixed 7 bytes from the suffix pointer. When the resolved hostname's final label is shorter than 7 bytes (e.g. names ending in .org, .com, .net, .io, or a trailing dot), the comparison reads 1-2 bytes past the string's NUL terminator. The hostname (query) is the caller-supplied name passed through the standard getaddrinfo()/dns_get_addr_info()/dns_resolve_name() path and is influenceable by operators or remote inputs (server names from configuration, parsed URLs, or app-facing interfaces). On a tightly-sized buffer with no slack (for example a userspace getaddrinfo call where the hostname is copied with k_usermode_string_alloc_copy to exactly strlen+1 bytes), the over-read crosses the allocation boundary; if that boundary is unmapped (guard page, memory-domain boundary under MPU, or an address sanitizer) the over-read faults, causing a denial of service. The over-read bytes are never returned, so there is no information disclosure. The flaw is compiled only when CONFIG_MDNS_RESOLVER is enabled, exists since v1.10.0, and is fixed by replacing the fixed-length memcmp with a NUL-safe strcmp(ptr, \".local\")."}],"affected":[{"vendor":"zephyrproject","product":"zephyr","collectionURL":"https://github.com/zephyrproject-rtos/zephyr","packageName":"zephyr","defaultStatus":"unaffected","versions":[{"version":"1.10.0","status":"affected","lessThan":"4.5.0","versionType":"semver"}]}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/448a21da12c9ea28f7fd12c6894e03a987b17a27","name":"Fix commit","tags":["patch"]},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-76jh-3j5f-9vq4","name":"GHSA-76jh-3j5f-9vq4"}],"metrics":[{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","baseScore":3.7,"baseSeverity":"LOW"}}],"problemTypes":[{"descriptions":[{"lang":"en","description":"bounds","cweId":"CWE-125","type":"CWE"}]}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-06T18:51:45.471859Z","id":"CVE-2026-10657","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-07-06T18:51:56.291Z"}}]}}