How severe is CVE-2026-7866?

CVE-2026-7866 has a CVSS 4.0 base score of 10.0, rated critical severity.

Is CVE-2026-7866 being actively exploited?

It is not currently listed in CISA's Known Exploited Vulnerabilities catalog, and no EPSS exploit-prediction score is available yet.

How do I fix CVE-2026-7866?

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

When was CVE-2026-7866 published?

CVE-2026-7866 was published on 2026-09-22.

CVE-2026-7866

CVE-2026-7866 is a critical-severity vulnerability with a CVSS 4.0 base score of 10.0. The underlying weakness is classified as CWE-121.

Key facts

Severity: Critical (CVSS 4.0 base score 10.0)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-121
Published: 2026-09-22
Last modified: 2026-09-22

Description

Stack-based Buffer Overflow vulnerability in RTI Connext Professional (Core Libraries) allows Overflow Buffers. This issue affects Connext Professional: from 7.4.0 before 7.7.0.1, from 7.0.0 before 7.3.1.6, from 6.1.0 before 6.1.*, from 6.0.0 before 6.0.*, from 5.3.0 before 5.3.*, from 5.2.0 before 5.2.*, from 4.3x before 5.1.*.

Frequently asked questions

What is CVE-2026-7866?: Stack-based Buffer Overflow vulnerability in RTI Connext Professional (Core Libraries) allows Overflow Buffers. This issue affects Connext Professional: from 7.4.0 before 7.7.0.1, from 7.0.0 before 7.3.1.6, from 6.1.0 before 6.1.*, from 6.0.0 before 6.0.*, from 5.3.0 before 5.3.*, from 5.2.0 before 5.2.*, from 4.3x before 5.1.*.
How severe is CVE-2026-7866?: CVE-2026-7866 has a CVSS 4.0 base score of 10.0, rated critical severity.
Is CVE-2026-7866 being actively exploited?: It is not currently listed in CISA's Known Exploited Vulnerabilities catalog, and no EPSS exploit-prediction score is available yet.
How do I fix CVE-2026-7866?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-7866 published?: CVE-2026-7866 was published on 2026-09-22.

References

https://www.rti.com/vulnerabilities/#cve-2026-7866

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