{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "3.3.0"
              },
              {
                "fixed": "4.4.2"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "07c6af3b8c35c1e49186578ca61a25c76e2fb308"
            },
            {
              "fixed": "3d578067652b12993bca13fb8e07dc45d062d4a5"
            }
          ],
          "repo": "https://github.com/zephyrproject-rtos/zephyr",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-2m6g-p3vx-p2fh"
  ],
  "database_specific": {
    "cna_assigner": "zephyr",
    "cwe_ids": [
      "CWE-125"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/13xxx/CVE-2026-13479.json"
  },
  "details": "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-\u003eBuffer/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.",
  "id": "CVE-2026-13479",
  "modified": "2026-08-28T11:30:32.807952258Z",
  "published": "2026-08-26T14:03:47.708Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/13xxx/CVE-2026-13479.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2m6g-p3vx-p2fh"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-13479"
    },
    {
      "type": "FIX",
      "url": "https://github.com/zephyrproject-rtos/zephyr/commit/3d578067652b12993bca13fb8e07dc45d062d4a5"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/zephyrproject-rtos/zephyr"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Out-of-bounds read in LoRaWAN clock-sync AppTimeAns downlink handler"
}