CVE REMEDIATION GUIDE
Review reviewCriticalResearch in progress

CVE-2026-10666 remediation guide

zephyrproject zephyr

parse_ipv4() in subsys/net/ip/utils.c (reached via net_ipaddr_parse() for strings of the form "a.b.c.d:port") copies the port substring into a fixed 17-byte stack buffer (char ipaddr[NET_IPV4_ADDR_LEN + 1]) using a length of str_len - end - 1, where str_len is the full, unbounded input length and end is only the (<=15-byte) offset of the ':' delimiter. Because the destination size is never consulted, a crafted address string with a long suffix after the colon (e.g. "1.2.3.4:" followed by hundreds of bytes) causes an out-of-bounds stack write whose length and contents are fully attacker-cont...

Open CVE record
Research in progress

A verified fixed-version field is not available. Use the linked NVD and supporting references, then confirm the vendor-supported path before changing production systems.

Productzephyrproject zephyr
Affected versions>= 1.9.0 < 4.5.0, >= 1.9.0 <= 4.4.1
Fixed versionsNo verified fixed-version field is available yet
Priority basisReview · CVSS 9.8 · EPSS 0.45%
01

Identify the affected asset

Confirm whether zephyrproject zephyr is installed, record the deployed version and installation path, and identify exposed interfaces.

  • Record the product name, package or appliance identifier, and installed version.
  • Identify internet-facing, administrative, API, and internal access paths.
  • Preserve the pre-change configuration and relevant service logs.
02

Validate the affected-version match

Compare the deployed version with the affected range: >= 1.9.0 < 4.5.0, >= 1.9.0 <= 4.4.1. Treat incomplete inventory results as unresolved.

03

Prioritize with independent signals

The CVSS severity warrants an early asset and exposure review. Combine this signal with asset criticality, exposure, compensating controls, and business impact.

04

Apply supported remediation

Follow the vendor advisory or supported update path. Current fixed-version status: No verified fixed-version field is available yet. Preserve configuration and rollback material before change.

05

Verify the result

Confirm the resulting version, service health, authentication and access paths, monitoring coverage, and relevant security logs.

  • Confirm the expected version and package state.
  • Run a functional health check for critical service paths.
  • Review authentication, error, application, and security monitoring logs.
  • Reassess exposure if the supported fix cannot be applied.

Operational boundary

This page does not replace the vendor advisory, support contract, change-management process, or recovery plan. Do not infer that an asset is unaffected from an incomplete inventory query or a missing fixed-version field.