{"id":"CVE-2026-12632","aliases":["EUVD-2026-61492","GHSA-frjr-h396-7wh4"],"status":"published","title":"Out-of-bounds read in Zephyr PTP message parsing from unvalidated message type","description":"Zephyr's Precision Time Protocol receive handler ptp_msg_post_recv() in subsys/net/lib/ptp/msg.c takes the 4-bit message type straight off the wire via ptp_msg_type() (msg-\u003eheader.type_major_sdo_id \u0026 0xF, range 0-15) and uses it to index the msg_size[] table. That table only defines entries up to PTP_MSG_MANAGEMENT (0xD), giving it ARRAY_SIZE == 14. Before the fix there was no upper-bound check, so the undefined types 0xE and 0xF indexed one or two int slots past the end of the array — an out-of-bounds read of adjacent read-only data.\n\nThe out-of-bounds value is then reused as a length: it gates msg_size[type] \u003e cnt, and when it is small or negative it makes cnt - msg_size[type] a large positive budget passed to msg_tlv_post_recv(), whose TLV loop then walks the message suffix past the received bytes, performing further out-of-bounds reads and in-place byte-swap writes on memory beyond the message slab.\n\nThe defect is reached directly from the network: ptp_port_event_gen() in subsys/net/lib/ptp/port.c reads a PTP frame with ptp_transport_recv() and calls ptp_msg_post_recv() with the attacker-chosen type. PTP uses UDP multicast or raw Ethernet (0x88F7) and is unauthenticated, so any host on the same link can trigger the indexing on a CONFIG_PTP-enabled node with no preconditions.\n\nThe reliably reproducible impact is a denial of service (fault/crash); a limited memory-corruption path exists but depends on the build-specific value adjacent to msg_size[], which the attacker cannot tune. The fix rejects type \u003e= ARRAY_SIZE(msg_size) with -EBADMSG before any indexing.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00285,"percentile":0.21184,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-125"],"published":"2026-08-18T20:55:43Z","modified":"2026-11-04T04:59:36Z","products":[{"vendor":"zephyrproject","product":"zephyr"},{"vendor":"zephyrproject-rtos","product":"zephyr"}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/30dabd4c2f2e3641732c00111cd80b5c524c0136","tags":["patch","fix"]},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-frjr-h396-7wh4","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/12xxx/CVE-2026-12632.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-12632","tags":["advisory"]},{"url":"https://github.com/zephyrproject-rtos/zephyr","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-12632","title":"Out-of-bounds read in Zephyr PTP message parsing from unvalidated message type","description":"Zephyr's Precision Time Protocol receive handler ptp_msg_post_recv() in subsys/net/lib/ptp/msg.c takes the 4-bit message type straight off the wire via ptp_msg_type() (msg-\u003eheader.type_major_sdo_id \u0026 0xF, range 0-15) and uses it to index the msg_size[] table. That table only defines entries up to PTP_MSG_MANAGEMENT (0xD), giving it ARRAY_SIZE == 14. Before the fix there was no upper-bound check, so the undefined types 0xE and 0xF indexed one or two int slots past the end of the array — an out-of-bounds read of adjacent read-only data.\n\nThe out-of-bounds value is then reused as a length: it gates msg_size[type] \u003e cnt, and when it is small or negative it makes cnt - msg_size[type] a large positive budget passed to msg_tlv_post_recv(), whose TLV loop then walks the message suffix past the received bytes, performing further out-of-bounds reads and in-place byte-swap writes on memory beyond the message slab.\n\nThe defect is reached directly from the network: ptp_port_event_gen() in subsys/net/lib/ptp/port.c reads a PTP frame with ptp_transport_recv() and calls ptp_msg_post_recv() with the attacker-chosen type. PTP uses UDP multicast or raw Ethernet (0x88F7) and is unauthenticated, so any host on the same link can trigger the indexing on a CONFIG_PTP-enabled node with no preconditions.\n\nThe reliably reproducible impact is a denial of service (fault/crash); a limited memory-corruption path exists but depends on the build-specific value adjacent to msg_size[], which the attacker cannot tune. The fix rejects type \u003e= ARRAY_SIZE(msg_size) with -EBADMSG before any indexing.","status":"published","published":"2026-08-18T20:55:43.955Z","modified":"2026-11-04T04:59:36.437Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-125"],"updated_at":"2026-11-04T05:21:48.223566Z"}],"euvd":[{"id":"EUVD-2026-61492","description":"Zephyr's Precision Time Protocol receive handler ptp_msg_post_recv() in subsys/net/lib/ptp/msg.c takes the 4-bit message type straight off the wire via ptp_msg_type() (msg-\u003eheader.type_major_sdo_id \u0026 0xF, range 0-15) and uses it to index the msg_size[] table. That table only defines entries up to PTP_MSG_MANAGEMENT (0xD), giving it ARRAY_SIZE == 14. Before the fix there was no upper-bound check, so the undefined types 0xE and 0xF indexed one or two int slots past the end of the array — an out-of-bounds read of adjacent read-only data.\n\nThe out-of-bounds value is then reused as a length: it gates msg_size[type] \u003e cnt, and when it is small or negative it makes cnt - msg_size[type] a large positive budget passed to msg_tlv_post_recv(), whose TLV loop then walks the message suffix past the received bytes, performing further out-of-bounds reads and in-place byte-swap writes on memory beyond the message slab.\n\nThe defect is reached directly from the network: ptp_port_event_gen() in subsys/net/lib/ptp/port.c reads a PTP frame with ptp_transport_recv() and calls ptp_msg_post_recv() with the attacker-chosen type. PTP uses UDP multicast or raw Ethernet (0x88F7) and is unauthenticated, so any host on the same link can trigger the indexing on a CONFIG_PTP-enabled node with no preconditions.\n\nThe reliably reproducible impact is a denial of service (fault/crash); a limited memory-corruption path exists but depends on the build-specific value adjacent to msg_size[], which the attacker cannot tune. The fix rejects type \u003e= ARRAY_SIZE(msg_size) with -EBADMSG before any indexing.","status":"published","published":"2026-08-18T20:55:43Z","modified":"2026-11-04T04:59:36Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-04T07:00:56.720215Z"}],"nvd":[{"id":"CVE-2026-12632","description":"Zephyr's Precision Time Protocol receive handler ptp_msg_post_recv() in subsys/net/lib/ptp/msg.c takes the 4-bit message type straight off the wire via ptp_msg_type() (msg-\u003eheader.type_major_sdo_id \u0026 0xF, range 0-15) and uses it to index the msg_size[] table. That table only defines entries up to PTP_MSG_MANAGEMENT (0xD), giving it ARRAY_SIZE == 14. Before the fix there was no upper-bound check, so the undefined types 0xE and 0xF indexed one or two int slots past the end of the array — an out-of-bounds read of adjacent read-only data.\n\nThe out-of-bounds value is then reused as a length: it gates msg_size[type] \u003e cnt, and when it is small or negative it makes cnt - msg_size[type] a large positive budget passed to msg_tlv_post_recv(), whose TLV loop then walks the message suffix past the received bytes, performing further out-of-bounds reads and in-place byte-swap writes on memory beyond the message slab.\n\nThe defect is reached directly from the network: ptp_port_event_gen() in subsys/net/lib/ptp/port.c reads a PTP frame with ptp_transport_recv() and calls ptp_msg_post_recv() with the attacker-chosen type. PTP uses UDP multicast or raw Ethernet (0x88F7) and is unauthenticated, so any host on the same link can trigger the indexing on a CONFIG_PTP-enabled node with no preconditions.\n\nThe reliably reproducible impact is a denial of service (fault/crash); a limited memory-corruption path exists but depends on the build-specific value adjacent to msg_size[], which the attacker cannot tune. The fix rejects type \u003e= ARRAY_SIZE(msg_size) with -EBADMSG before any indexing.","status":"published","published":"2026-08-18T21:16:33.783Z","modified":"2026-11-04T05:18:40.56Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-125"],"updated_at":"2026-11-04T06:53:20.502063Z"}],"osv":[{"id":"CVE-2026-12632","title":"Out-of-bounds read in Zephyr PTP message parsing from unvalidated message type","description":"Zephyr's Precision Time Protocol receive handler ptp_msg_post_recv() in subsys/net/lib/ptp/msg.c takes the 4-bit message type straight off the wire via ptp_msg_type() (msg-\u003eheader.type_major_sdo_id \u0026 0xF, range 0-15) and uses it to index the msg_size[] table. That table only defines entries up to PTP_MSG_MANAGEMENT (0xD), giving it ARRAY_SIZE == 14. Before the fix there was no upper-bound check, so the undefined types 0xE and 0xF indexed one or two int slots past the end of the array — an out-of-bounds read of adjacent read-only data.\n\nThe out-of-bounds value is then reused as a length: it gates msg_size[type] \u003e cnt, and when it is small or negative it makes cnt - msg_size[type] a large positive budget passed to msg_tlv_post_recv(), whose TLV loop then walks the message suffix past the received bytes, performing further out-of-bounds reads and in-place byte-swap writes on memory beyond the message slab.\n\nThe defect is reached directly from the network: ptp_port_event_gen() in subsys/net/lib/ptp/port.c reads a PTP frame with ptp_transport_recv() and calls ptp_msg_post_recv() with the attacker-chosen type. PTP uses UDP multicast or raw Ethernet (0x88F7) and is unauthenticated, so any host on the same link can trigger the indexing on a CONFIG_PTP-enabled node with no preconditions.\n\nThe reliably reproducible impact is a denial of service (fault/crash); a limited memory-corruption path exists but depends on the build-specific value adjacent to msg_size[], which the attacker cannot tune. The fix rejects type \u003e= ARRAY_SIZE(msg_size) with -EBADMSG before any indexing.","status":"published","published":"2026-08-18T20:55:43.955Z","modified":"2026-11-05T08:03:57.942111173Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-125"],"updated_at":"2026-11-05T09:08:14.330889Z"}]}}