{"affected":[{"defaultStatus":"unaffected","ecosystem":"https://github.com/zephyrproject-rtos/zephyr","packageName":"zephyr","product":"zephyr","source":"CNA: zephyr","vendor":"zephyrproject","versions":[{"lessThan":"4.3.2","status":"affected","version":"3.3.0","versionType":"semver"},{"lessThan":"4.4.2","status":"affected","version":"4.4.0","versionType":"semver"}]}],"cpeConfigurations":[{"negate":false,"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:*","versionEndExcluding":"4.4.2","versionStartIncluding":"3.3.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"OR"}],"cveId":"CVE-2026-13479","cwes":["CWE-125"],"description":"The LoRaWAN application-layer clock-synchronization service parses downlinks in clock_sync_package_callback() (subsys/lorawan/services/clock_sync.c). Its command loop only guarantees that the one-byte command id is in bounds; for the CLOCK_SYNC_CMD_APP_TIME (AppTimeAns) command the handler then reads a 4-byte time correction via sys_get_le32() plus a 1-byte token without checking that 5 bytes remain in the receive buffer (len - rx_pos). A short or crafted AppTimeAns therefore reads up to 5 bytes past the end of the decrypted payload.\n\nThe payload (rx_buf/len) is the decrypted application frame delivered to the registered downlink callback (mcps_indication->Buffer/BufferSize). Reaching the handler requires a frame on the clock-sync port that passes LoRaWAN's MAC integrity check and FRMPayload decryption, so the practical attacker is a malicious or compromised network/application server (the designated sender of AppTimeAns) or a party holding the session keys, rather than an arbitrary radio listener.\n\nThe over-read is bounded: the backing store is a fixed 255-byte static buffer, so the few stray bytes do not fault, and the read values (time_correction, token) are used only internally and never transmitted, so there is no disclosure to the attacker and no crash. The sole effect is that a stale token matching ctx.req_token can apply a garbage time_correction to the device's own clock offset (ctx.time_offset), a minor integrity impact confined to the victim's time estimate. The fix adds an explicit length check that drops a too-short AppTimeAns. Note the sibling one-byte reads in the periodicity and force-resync handlers remain unguarded with the same negligible impact.","epss":{"date":"2026-11-03","percentile":0.13384,"score":0.00226},"exploits":[{"kind":"exploit","source":"vulnerabilities@zephyrproject.org","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2m6g-p3vx-p2fh"}],"kev":null,"metrics":[{"score":3.1,"severity":"low","source":"CNA: zephyr","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","version":"3.1"},{"score":4.3,"severity":"medium","source":"NVD: nvd@nist.gov","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","version":"3.1"},{"score":3.1,"severity":"low","source":"NVD: vulnerabilities@zephyrproject.org","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","version":"3.1"}],"modifiedAt":1793769522320,"publishedAt":1787753027708,"references":[{"source":"CNA: zephyr","tags":["patch"],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/3d578067652b12993bca13fb8e07dc45d062d4a5"},{"source":"CNA: zephyr","tags":[],"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2m6g-p3vx-p2fh"},{"source":"vulnerabilities@zephyrproject.org","tags":["Patch"],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/3d578067652b12993bca13fb8e07dc45d062d4a5"},{"source":"vulnerabilities@zephyrproject.org","tags":["Exploit","Patch","Vendor Advisory"],"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2m6g-p3vx-p2fh"}],"remediation":[{"kind":"fix","source":"CNA: zephyr","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/zephyrproject-rtos/zephyr/commit/3d578067652b12993bca13fb8e07dc45d062d4a5"},{"kind":"fix","source":"vulnerabilities@zephyrproject.org","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/zephyrproject-rtos/zephyr/commit/3d578067652b12993bca13fb8e07dc45d062d4a5"},{"kind":"fix","source":"vulnerabilities@zephyrproject.org","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2m6g-p3vx-p2fh"}],"revision":"de401ba727e7c9f2961994eee609bdecb9bf493ab5cd2875550fcdf22da307ba","sources":[{"modifiedAt":1793768399325,"name":"CNA: zephyr","retrievedAt":1793769040593,"url":"https://www.cve.org/CVERecord?id=CVE-2026-13479"},{"modifiedAt":1793769522320,"name":"NVD","retrievedAt":1793772962763,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-13479"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793769047127,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-13479"}],"ssvc":{"assessedAt":1787759048607,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"Out-of-bounds read in LoRaWAN clock-sync AppTimeAns downlink handler","updatedAt":1793772962763}