Medium 5.8Published Jul 16, 2026

CVE-2026-15449TOCTOU double copyin in illumos dld ioctl handling causes kernel heap corruption

Updated under an hour ago (Oct 26, 2026, 10:20 PM ET)

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Exploited in the last 30 days

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.

CVSS: 5.8 MEDIUM (v4.0, CNA)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
Weakness (CWE): CWE-367, CWE-122
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: illumos
NVD analysis: Deferred
Record last updated: Jul 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

illumos illumos-gate illumos:gate (from the name)	from eae72b5b807baa9116e64502cbb278edf15f3146 before 6959feb5b430411a4809b06c53dcdb42fb525eac; fixed at 6959feb5b430411a4809b06c53dcdb42fb525eac	CNA record
OmniOS OmniOS omnios:omnios (from the name)	from any before r151054; from r151058 before r151058j; fixed at r151058j; from r151056 before r151056aj; fixed at r151056aj; from r151054 before r151054bj; fixed at r151054bj	CNA record
Triton Data Center SmartOS triton_data_center:smartos (from the name)	from any before 202060709; fixed at 20260709	CNA record

References

References

https://illumos.topicbox.com/groups/developer/T923147fae854a738-M03c29e1be33dac2a5e3d9535/18020-double-copyin-of-dldioc-consumers	mailing-list
https://illumos.org/issues/18020	issue-tracking
https://github.com/illumos/illumos-gate/commit/6959feb5b430411a4809b06c53dcdb42fb525eac	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.