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PatchSiren cyber security CVE debrief

CVE-2026-35058 OpenVPN CVE debrief

CVE-2026-35058 is a medium-severity vulnerability in OpenVPN, affecting versions 2.6.0 through 2.6.19 and 2.7_alpha1 through 2.7.1. The vulnerability is caused by improper validation of packet length during tls-crypt-v2 key extraction, allowing authenticated attackers to trigger a fatal assertion and cause a denial of service via a specially crafted packet. The CVSS score for this vulnerability is 6.9, indicating a medium severity.

Vendor
OpenVPN
Product
Unknown
CVSS
MEDIUM 6.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-08
Original CVE updated
2026-08-11
Advisory published
2026-06-08
Advisory updated
2026-08-11

Who should care

Users of OpenVPN versions 2.6.0 through 2.6.19 and 2.7_alpha1 through 2.7.1 should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The vulnerability is caused by improper validation of packet length during tls-crypt-v2 key extraction in OpenVPN. This allows authenticated attackers to trigger a fatal assertion and cause a denial of service via a specially crafted packet.

Defensive priority

High

Recommended defensive actions

  • Update to a fixed version of OpenVPN
  • Restrict access to OpenVPN to only trusted users

Evidence notes

The CVE record and NVD detail pages provide additional information about this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-35058 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-35058

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-35058 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-35058

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.