Vulnerability · Published Jul 16, 2026 · Assigned by illumos
CVE-2026-15449TOCTOU double copyin in illumos dld ioctl handling causes kernel heap corruption
Medium 5.8
In plain English
A medium-severity heap buffer overflow in illumos-gate from illumos. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities).
Official description
A time-of-check to time-of-use (TOCTOU) flaw in the illumos data-link pseudo-driver (dld) affects handling of the DLDIOC_GETMACPROP and DLDIOC_SETMACPROP ioctls on /dev/dld. drv_ioc_prop_common() in usr/src/uts/common/io/dld/dld_drv.c copies the dld_ioc_macprop_t ioctl header in once to read its pr_valsize field, sizes and allocates a kernel heap buffer from that value, and then copies the full request in a second time from the same unprivileged user address. A concurrent thread can enlarge pr_valsize between the two copyins, so the second copyin and the subsequent property handling write beyond the end of the undersized allocation and corrupt the kernel heap. An unprivileged local user, including one confined to a non-global zone that owns a datalink, can trigger this to panic the system. The resulting kernel heap corruption may be usable for further compromise.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| illumos | illumos-gate | eae72b5b807baa9116e64502cbb278edf15f3146 – before 6959feb5b430411a4809b06c53dcdb42fb525eac |
| OmniOS | OmniOS | any – before r151054r151058 – before r151058jr151056 – before r151056ajr151054 – before r151054bj |
| Triton Data Center | SmartOS | any – before 202060709 |
Weakness: CWE-367, CWE-122 · Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N