CVE-2026-45812 Apache NimBLE vulnerability
Incorrect Calculation of Buffer Size vulnerability in Apache NimBLE when processing Legacy Advertising Report HCI event. When a single HCI advertising report event bundles multiple reports, NimBLE miscalculated the offset to the next report. This can cause the host to read past the end of the buffer and deliver a GAP event with bogus data to the application. Severity is low: NimBLE's own controller never batches multiple reports into one event, so this only matters when NimBLE's host is paired with a third-party controller that does. This issue affects Apache NimBLE: through 1.9.0. Users are recommended to upgrade to version 1.10.0, which fixes the issue.
Quick answer
Apache Software Foundation Apache NimBLE should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- <= 1.9.0
Fixed versions
- Apply the latest vendor-supported patched version.
How to fix it
CVE-2026-45812 affects Apache NimBLE and involves security-control failure. Successful exploitation may affect the confidentiality, integrity, or availability of the affected workflow. Prioritize deployments that process untrusted input, expose the affected feature, or hold sensitive data. No confirmed fixed version is recorded for CVE-2026-45812; follow the linked vendor advisory, apply its mitigation, and update Apache NimBLE as soon as a supported patched release is available.
- Inventory every deployment, device, package, plugin, container, build, and environment that uses Apache NimBLE.
- Compare the installed version with the recorded affected range: <= 1.9.0.
- No confirmed fixed version is recorded for CVE-2026-45812; follow the linked vendor advisory, apply its mitigation, and update Apache NimBLE as soon as a supported patched release is available.
- Until patched, reduce public exposure, disable the affected workflow where practical, and allow access only from trusted users and systems.
- Review configuration, roles, tokens, network paths, and exposed endpoints connected to Apache NimBLE; remove access that is not required.
- Review application, system, proxy, and audit logs for requests and behavior linked to the affected feature and CVE.
- If exploitation is suspected, isolate affected assets, preserve evidence, rotate exposed credentials or keys, restore trusted data, and rebuild compromised systems before returning them to service.
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Verify the fix
- Confirm every affected asset now runs the fixed vendor-supported release or has the documented mitigation for CVE-2026-45812 in place.
- Use a safe regression test to confirm the affected security-control failure path no longer produces the vulnerable behavior.
- Confirm temporary access controls, endpoint restrictions, network blocks, and least-privilege settings remain effective after the update.
- Review post-remediation logs and rerun Fixnx plus the relevant package, dependency, firmware, browser, or product-specific security check.
- Document affected assets, versions, changes, validation evidence, reviewed logs, and any credential rotation, cleanup, or replacement completed.
Trusted references
FAQ
What is affected by CVE-2026-45812?
Apache Software Foundation Apache NimBLE versions listed as affected should be reviewed: <= 1.9.0.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
How are Fixnx security risk categories chosen?
Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.