How severe is CVE-2026-40215?

CVE-2026-40215 has a CVSS 4.0 base score of 6.1, rated medium severity.

Is CVE-2026-40215 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40215?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-40215 have an EU (EUVD) identifier?

Yes. CVE-2026-40215 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35200.

When was CVE-2026-40215 published?

CVE-2026-40215 was published on 2026-06-08 and last updated on 2026-06-17.

CVE-2026-40215

CVE-2026-40215 is a medium-severity vulnerability with a CVSS 4.0 base score of 6.1. 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-125.

Key facts

Severity: Medium (CVSS 4.0 base score 6.1)
EPSS exploit prediction: 0% (23rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-35200
Weakness: CWE-125
Published: 2026-06-08
Last modified: 2026-06-17

Description

A race condition in OpenVPN 2.6.0 through 2.6.19 and 2.7_alpha1 through 2.7.1 allows remote attackers to potentially cause a server crash or leak heap memory via a use-after-free triggered during TLS session promotion.

Frequently asked questions

What is CVE-2026-40215?: A race condition in OpenVPN 2.6.0 through 2.6.19 and 2.7_alpha1 through 2.7.1 allows remote attackers to potentially cause a server crash or leak heap memory via a use-after-free triggered during TLS session promotion.
How severe is CVE-2026-40215?: CVE-2026-40215 has a CVSS 4.0 base score of 6.1, rated medium severity.
Is CVE-2026-40215 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40215?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-40215 have an EU (EUVD) identifier?: Yes. CVE-2026-40215 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35200.
When was CVE-2026-40215 published?: CVE-2026-40215 was published on 2026-06-08 and last updated on 2026-06-17.

References

Other CWE-125 (Out-of-bounds Read) vulnerabilities

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CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

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