{"id":"CVE-2026-10672","state":"PUBLISHED","title":"Unterminated URI buffer causes out-of-bounds read in LwM2M firmware pull (Package URI)","description":"subsys/net/lib/lwm2m/lwm2m_pull_context.c copied the firmware-update Package URI into a fixed static buffer (context.uri, size CONFIG_LWM2M_SWMGMT_PACKAGE_URI_LEN, default 128) with memcpy(context.uri, uri, LWM2M_PACKAGE_URI_LEN), copying exactly the destination size with no length validation. The Firmware-Update object stores the server-supplied Package URI (/5/0/1) in a 255-byte buffer, so a LwM2M management server (or an on-path attacker on a session lacking strong DTLS) can WRITE a URI of 128-254 characters; only the first 128 bytes are then copied into context.uri with no NUL terminator. That buffer is subsequently consumed as a C string by http_parser_parse_url(context.uri, strlen(context.uri), ...), strlen-based CoAP URI-path/PROXY-URI option appends, and lwm2m_parse_peerinfo(), causing an out-of-bounds read of adjacent static memory. The over-read bytes are appended to outbound CoAP requests (information disclosure of adjacent device memory to the server/proxy) and can crash the device (denial of service). The vulnerable copy was introduced by the pull-context refactor (first released in v3.0.0) and is present through v4.4.0; the default-on CONFIG_LWM2M_FIRMWARE_UPDATE_PULL_SUPPORT path is affected. The fix adds a strlen(uri) >= sizeof(context.uri) check returning -ENOMEM and switches to strcpy(), guaranteeing a bounded, NUL-terminated buffer.","publishedAt":"2026-07-14T15:02:04.482Z","updatedAt":"2026-10-15T22:10:15.606Z","severity":{"score":8.2,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L","source":"zephyr"},"assigner":"zephyr","products":["zephyrproject zephyr"],"affected":[{"vendor":"zephyrproject","product":"zephyr","packageName":"zephyr","defaultStatus":"unaffected","versions":[{"version":"3.0.0","status":"affected","lessThan":"4.3.1","versionType":"semver"},{"version":"4.4.0","status":"affected","lessThan":"4.4.1","versionType":"semver"}],"collectionURL":"https://github.com/zephyrproject-rtos/zephyr","programFiles":["subsys/net/lib/lwm2m/lwm2m_pull_context.c"]}],"references":["https://github.com/zephyrproject-rtos/zephyr/commit/99a164df5cea5af76e32b57c6d51854f018969a2","https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-rf6j-4mpp-j9mf"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:10:33.477Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/10xxx/CVE-2026-10672.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-10672","state":"PUBLISHED","datePublished":"2026-07-14T15:02:04.482Z","dateUpdated":"2026-10-15T22:10:15.606Z","assignerShortName":"zephyr","assignerOrgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","dateReserved":"2026-06-02T15:25:35.843Z"},"containers":{"cna":{"title":"Unterminated URI buffer causes out-of-bounds read in LwM2M firmware pull (Package URI)","descriptions":[{"lang":"en","value":"subsys/net/lib/lwm2m/lwm2m_pull_context.c copied the firmware-update Package URI into a fixed static buffer (context.uri, size CONFIG_LWM2M_SWMGMT_PACKAGE_URI_LEN, default 128) with memcpy(context.uri, uri, LWM2M_PACKAGE_URI_LEN), copying exactly the destination size with no length validation. The Firmware-Update object stores the server-supplied Package URI (/5/0/1) in a 255-byte buffer, so a LwM2M management server (or an on-path attacker on a session lacking strong DTLS) can WRITE a URI of 128-254 characters; only the first 128 bytes are then copied into context.uri with no NUL terminator. That buffer is subsequently consumed as a C string by http_parser_parse_url(context.uri, strlen(context.uri), ...), strlen-based CoAP URI-path/PROXY-URI option appends, and lwm2m_parse_peerinfo(), causing an out-of-bounds read of adjacent static memory. The over-read bytes are appended to outbound CoAP requests (information disclosure of adjacent device memory to the server/proxy) and can crash the device (denial of service). The vulnerable copy was introduced by the pull-context refactor (first released in v3.0.0) and is present through v4.4.0; the default-on CONFIG_LWM2M_FIRMWARE_UPDATE_PULL_SUPPORT path is affected. The fix adds a strlen(uri) >= sizeof(context.uri) check returning -ENOMEM and switches to strcpy(), guaranteeing a bounded, NUL-terminated buffer."}],"affected":[{"vendor":"zephyrproject","product":"zephyr","packageName":"zephyr","defaultStatus":"unaffected","versions":[{"version":"3.0.0","status":"affected","lessThan":"4.3.1","versionType":"semver"},{"version":"4.4.0","status":"affected","lessThan":"4.4.1","versionType":"semver"}],"collectionURL":"https://github.com/zephyrproject-rtos/zephyr","programFiles":["subsys/net/lib/lwm2m/lwm2m_pull_context.c"]}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/99a164df5cea5af76e32b57c6d51854f018969a2","name":"Fix commit","tags":["patch"]},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-rf6j-4mpp-j9mf","name":"GHSA-rf6j-4mpp-j9mf"}],"metrics":[{"cvssV3_1":{"baseScore":8.2,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","description":"bounds","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"zephyr","orgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","dateUpdated":"2026-10-15T22:10:15.606Z"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-rf6j-4mpp-j9mf","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-14T15:28:04.126168Z","id":"CVE-2026-10672","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-14T15:28:37.269Z"}}]}}}