Is CVE-2026-40215 in the CISA KEV catalog?

No. CVE-2026-40215 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-40215?

CVE-2026-40215 has a CVSS v4 base score of 6.1 (MEDIUM).

What is the EPSS score for CVE-2026-40215?

CVE-2026-40215 has an EPSS score of 0.31% (23th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40215?

Upgrade openvpn on debian 11 to 2.5.1-3+deb11u3 or later. Fixes are available for 2 affected products.

CVE & CISA-KEV Catalog

CVE-2026-40215

MEDIUM

6.1

CVSS v4

NVD

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.

CWE-125Out-of-bounds Read CWE-416Use After Free

How to fix

Remediation Available

openvpnDebian

Fixed in:2.5.1-3+deb11u3CVE-2026-40215

Fixed in:2.6.14-0+deb12u1CVE-2026-40215

Fixed in:2.6.14-1+deb13u2CVE-2026-40215

Fixed in:2.7.2-1CVE-2026-40215

openvpnUbuntu

Fixed in:2.5.11-0ubuntu0.22.04.3USN-8286-1

Fixed in:2.6.19-0ubuntu0.24.04.2USN-8286-1

Fixed in:2.6.19-0ubuntu0.25.10.2USN-8286-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v4 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredLow

User InteractionNone

Impact

CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:N/VA:H/SC:L/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Exploit Intelligence

0.31%probability of exploitation in 30 days

23rdpercentile

Low risk: more likely to be exploited than 23% of all known CVEs.

References

Other references3

Related Vulnerabilities

Other CWE-125 (Out-of-bounds Read) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2014-0160	High	7.5	100%	KEV	Fix
CVE-2025-5777	High	7.5	100%	KEV + Ransom	Fix
CVE-2021-4034	High	7.8	95%	KEV	Fix
CVE-2023-21769	High	7.5	92%	-	Fix
CVE-2023-49285	High	8.6	89%	-	Fix
CVE-2020-8794	Critical	9.8	89%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-17.