CVE-2026-45811 Apache Software Foundation CVE debrief

Who should care

Users of Apache NimBLE versions through 1.9.0 should be aware of this vulnerability and take steps to upgrade to version 1.10.0. This vulnerability requires either a misconfigured pool size or a malicious/compromised controller on the other end of the HCI socket link, not over-the-air Bluetooth access.

Technical summary

The CVE-2026-45811 vulnerability is a Buffer Copy without Checking Size of Input vulnerability in Apache NimBLE. The HCI socket transport did not check whether a received HCI event would fit the configured event pool before copying it, allowing a buffer overflow. The CVSS score for this vulnerability is 7.5, with a HIGH severity rating. The vulnerability was published on 2026-07-24T13:18:23.847Z and last modified on 2026-07-27T14:41:24.173Z.

Defensive priority

Medium

Recommended defensive actions

• Upgrade to version 1.10.0 of Apache NimBLE
• Review and adjust HCI socket transport configurations
• Monitor for suspicious HCI event activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-07-24T13:18:23.847Z and was last modified on 2026-07-27T14:41:24.173Z. The NVD entry is currently Analyzed. The source detail is limited, so evidence limits should be considered when verifying this vulnerability. Defenders should verify the affected scope, severity, and vendor guidance with official sources. The HCI socket transport did not check whether a received HCI event would fit the configured event pool before copying it, allowing a buffer overflow. This issue affects Apache NimBLE through 1.9.0. Users are recommended to upgrade to version 1.10.0, which fixes the issue. The CVSS score for this vulnerability is 7.5, with a HIGH severity rating.

Official resources