{
  "cveId": "CVE-2026-68124",
  "url": "https://patchblox.com/security/cve/CVE-2026-68124",
  "summary": "CVE-2026-68124 is fixed in 17 products on 1 platform, first by DEBIAN-CVE-2026-68124, released August 11, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "mctp: serial: handle zero-length frames to prevent rx buffer overflow",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  mctp: serial: handle zero-length frames to prevent rx buffer overflow  The MCTP serial receive state machine reads a frame length byte in mctp_serial_push_header() case 2 and validates it upper-bound-only:  \tif (c \u003E MCTP_SERIAL_FRAME_MTU) { \t\tdev-\u003Erxstate = STATE_ERR; \t} else { \t\tdev-\u003Erxlen = c; \t\tdev-\u003Erxpos = 0; \t\tdev-\u003Erxstate = STATE_DATA; \t\t... \t}  A length of zero passes this check, so rxlen is set to 0 and the state machine advances to STATE_DATA. In mctp_serial_push() STATE_DATA, the incoming byte is stored and rxpos incremented before the terminator is  \tdev-\u003Erxbuf[dev-\u003Erxpos] = c; \tdev-\u003Erxpos\u002B\u002B; \tdev-\u003Erxstate = STATE_DATA; \tif (dev-\u003Erxpos == dev-\u003Erxlen) { \t\tdev-\u003Erxpos = 0; \t\tdev-\u003Erxstate = STATE_TRAILER; \t}  With rxlen == 0 the \u0022rxpos == rxlen\u0022 terminator can never fire (rxpos is already 1 on the first data byte), so subsequent bytes are written past the end of the fixed 74-byte rxbuf, which is the last member of the netdev private area. Every following data byte is an attacker-controlled 1-byte out-of-bounds heap write, and the overflow continues until a frame (0x7e) or escape byte resets the parser -- effectively unbounded.  Reaching this requires CAP_NET_ADMIN to attach the N_MCTP line discipline and bring the resulting mctpserialN netdev up, after which the bytes arrive via the tty receive path.  Route a zero-length frame straight to STATE_TRAILER instead of STATE_DATA. The trailer/framing bytes are still consumed, and the frame resolves to a zero-length skb that the MCTP core rejects; the parser never enters STATE_DATA with rxlen == 0, so the out-of-bounds write can no longer occur.  KASAN, on a frame of 0x7e 0x01 0x00 followed by data bytes (before this change):    UBSAN: array-index-out-of-bounds in drivers/net/mctp/mctp-serial.c:370   index 74 is out of range for type \u0027u8 [74]\u0027   BUG: KASAN: slab-out-of-bounds in mctp_serial_tty_receive_buf   Write of size 1 at addr ... by task kworker/u16:0    mctp_serial_tty_receive_buf    tty_ldisc_receive_buf    flush_to_ldisc   Allocated by task 152:    alloc_netdev_mqs    mctp_serial_open  v2: route zero-length frames to STATE_TRAILER instead of STATE_ERR so     the trailer/framing bytes are still consumed (Jeremy Kerr).  Found by 0sec automated security-research tooling (https://0sec.ai).",
  "published": "2026-08-10T13:19:57Z",
  "severity": "Important",
  "cvss": 9.6,
  "cvssVector": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
  "epss": 0.00343,
  "epssPercentile": 0.28026,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-68124",
  "fixes": [
    {
      "platform": "linux",
      "product": "dtb-aarch64",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-64kb",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-64kb",
      "release": "sles 15.7",
      "fixedVersion": "6.4.0-150700.53.81.1",
      "fix": "SUSE-SU-2026:4254-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4254-1",
      "released": "2026-10-07T22:31:36Z"
    },
    {
      "platform": "linux",
      "product": "kernel-64kb",
      "release": "sles 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "SUSE-SU-2026:23902-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23902-1",
      "released": "2026-09-22T14:23:31Z"
    },
    {
      "platform": "linux",
      "product": "kernel-azure",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-azure",
      "release": "sles 15.7",
      "fixedVersion": "6.4.0-150700.53.81.1",
      "fix": "SUSE-SU-2026:4254-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4254-1",
      "released": "2026-10-07T22:31:36Z"
    },
    {
      "platform": "linux",
      "product": "kernel-azure",
      "release": "sles 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "SUSE-SU-2026:23902-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23902-1",
      "released": "2026-09-22T14:23:31Z"
    },
    {
      "platform": "linux",
      "product": "kernel-default",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-default",
      "release": "sles 15.7",
      "fixedVersion": "6.4.0-150700.53.81.1",
      "fix": "SUSE-SU-2026:4254-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4254-1",
      "released": "2026-10-07T22:31:36Z"
    },
    {
      "platform": "linux",
      "product": "kernel-default",
      "release": "sles 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "SUSE-SU-2026:23902-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23902-1",
      "released": "2026-09-22T14:23:31Z"
    },
    {
      "platform": "linux",
      "product": "kernel-default-base",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1.160000.2.22",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-default-base",
      "release": "sles 15.7",
      "fixedVersion": "6.4.0-150700.53.81.1.150700.17.45.1",
      "fix": "SUSE-SU-2026:4254-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4254-1",
      "released": "2026-10-07T22:31:36Z"
    },
    {
      "platform": "linux",
      "product": "kernel-default-base",
      "release": "sles 16.0",
      "fixedVersion": "6.12.0-160000.38.1.160000.2.23",
      "fix": "SUSE-SU-2026:23902-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23902-1",
      "released": "2026-09-22T14:23:31Z"
    },
    {
      "platform": "linux",
      "product": "kernel-docs",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-docs",
      "release": "sles 15.7",
      "fixedVersion": "6.4.0-150700.53.81.1",
      "fix": "SUSE-SU-2026:4254-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4254-1",
      "released": "2026-10-07T22:31:36Z"
    },
    {
      "platform": "linux",
      "product": "kernel-docs",
      "release": "sles 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "SUSE-SU-2026:23902-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23902-1",
      "released": "2026-09-22T14:23:31Z"
    },
    {
      "platform": "linux",
      "product": "kernel-kvmsmall",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-kvmsmall",
      "release": "sles 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "SUSE-SU-2026:23902-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23902-1",
      "released": "2026-09-22T14:23:31Z"
    },
    {
      "platform": "linux",
      "product": "kernel-livepatch-SLE15-SP7-RT_Update_20",
      "release": "sles 15.7",
      "fixedVersion": "1-150700.1.3.1",
      "fix": "SUSE-SU-2026:4120-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4120-1",
      "released": "2026-09-10T09:31:34Z"
    },
    {
      "platform": "linux",
      "product": "kernel-livepatch-SLE15-SP7_Update_21",
      "release": "sles 15.7",
      "fixedVersion": "1-150700.15.3.1",
      "fix": "SUSE-SU-2026:4254-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4254-1",
      "released": "2026-10-07T22:31:36Z"
    },
    {
      "platform": "linux",
      "product": "kernel-obs-build",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-obs-build",
      "release": "sles 15.7",
      "fixedVersion": "6.4.0-150700.53.81.1",
      "fix": "SUSE-SU-2026:4254-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4254-1",
      "released": "2026-10-07T22:31:36Z"
    },
    {
      "platform": "linux",
      "product": "kernel-obs-qa",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-obs-qa",
      "release": "sles 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "SUSE-SU-2026:23902-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23902-1",
      "released": "2026-09-22T14:23:31Z"
    },
    {
      "platform": "linux",
      "product": "kernel-rt",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-source",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-source",
      "release": "sles 15.7",
      "fixedVersion": "6.4.0-150700.53.81.1",
      "fix": "SUSE-SU-2026:4254-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4254-1",
      "released": "2026-10-07T22:31:36Z"
    },
    {
      "platform": "linux",
      "product": "kernel-source",
      "release": "sles 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "SUSE-SU-2026:23902-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23902-1",
      "released": "2026-09-22T14:23:31Z"
    },
    {
      "platform": "linux",
      "product": "kernel-syms",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-syms",
      "release": "sles 15.7",
      "fixedVersion": "6.4.0-150700.53.81.1",
      "fix": "SUSE-SU-2026:4254-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4254-1",
      "released": "2026-10-07T22:31:36Z"
    },
    {
      "platform": "linux",
      "product": "kernel-syms",
      "release": "sles 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "SUSE-SU-2026:23902-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23902-1",
      "released": "2026-09-22T14:23:31Z"
    },
    {
      "platform": "linux",
      "product": "kernel-zfcpdump",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "OPENSUSE-SU-2026:21910-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21910-1",
      "released": "2026-09-22T15:26:20Z"
    },
    {
      "platform": "linux",
      "product": "kernel-zfcpdump",
      "release": "sles 15.7",
      "fixedVersion": "6.4.0-150700.53.81.1",
      "fix": "SUSE-SU-2026:4254-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4254-1",
      "released": "2026-10-07T22:31:36Z"
    },
    {
      "platform": "linux",
      "product": "kernel-zfcpdump",
      "release": "sles 16.0",
      "fixedVersion": "6.12.0-160000.38.1",
      "fix": "SUSE-SU-2026:23902-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23902-1",
      "released": "2026-09-22T14:23:31Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.1.187-1",
      "fix": "DEBIAN-CVE-2026-68124",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-68124",
      "released": "2026-08-11T16:03:09Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.101-1",
      "fix": "DEBIAN-CVE-2026-68124",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-68124",
      "released": "2026-08-11T16:03:09Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.1.6-1",
      "fix": "DEBIAN-CVE-2026-68124",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-68124",
      "released": "2026-08-11T16:03:09Z"
    },
    {
      "platform": "linux",
      "product": "linux-6.12",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.12.101-1~deb12u1",
      "fix": "DEBIAN-CVE-2026-68124",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-68124",
      "released": "2026-08-11T16:03:09Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}