How severe is CVE-2026-45811?

CVE-2026-45811 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-45811 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-45811?

CVE-2026-45811 affects Apache Nimble. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-45811?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-45811 published?

CVE-2026-45811 was published on 2026-07-24 and last updated on 2026-07-27.

CVE-2026-45811

CVE-2026-45811 is a high-severity vulnerability in Apache Nimble with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-120.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (27th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Apache Nimble
Published: 2026-07-24
Last modified: 2026-07-27

Description

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') 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. Severity is low: exploitation 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. This issue affects Apache NimBLE: through 1.9.0. Users are recommended to upgrade to version 1.10.0, which fixes the issue.

Frequently asked questions

What is CVE-2026-45811?: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') 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. Severity is low: exploitation 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. This issue affects Apache NimBLE: through 1.9.0. Users are recommended to upgrade to version 1.10.0, which fixes the issue.
How severe is CVE-2026-45811?: CVE-2026-45811 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-45811 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-45811?: CVE-2026-45811 affects Apache Nimble. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-45811?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-45811 published?: CVE-2026-45811 was published on 2026-07-24 and last updated on 2026-07-27.

References

Affected products (1)

cpe:2.3:a:apache:nimble:*:*:*:*:*:*:*:*

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