CVE-2026-10666
Stack buffer overflow in Zephyr IPv4 address parser enabling memory corruption.
Is CVE-2026-10666 being exploited?
Not confirmed. CVE-2026-10666 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.65% probability of exploitation in the next 30 days.
How severe is CVE-2026-10666?
CVE-2026-10666 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-10666?
Yes. A fix has been recorded for CVE-2026-10666. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-10666 affect?
CVE-2026-10666 affects Zephyr RTOS v1.9.0–v4.4.0, Devices using Zephyr network stack, Apps using zsock_getaddrinfo or eswifi DNS path. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-10666?
Update Zephyr to the patched release ASAP; validate/truncate address inputs and restrict untrusted name resolution.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Crafted 'a.b.c.d:longsuffix' address causes out-of-bounds stack write via socket/DNS paths, enabling DoS or potential remote code execution.
Immediate action required
- affected>= 1.9.0 and < 4.5.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.