HIGH 7.5 Microsoft

CVE-2026-21637

HackerOne: CVE-2026-21637 TLS PSK/ALPN Callback Exceptions Bypass Error Handlers

Microsoft Security Update 2026-Apr: HackerOne: CVE-2026-21637 TLS PSK/ALPN Callback Exceptions Bypass Error Handlers

Affected Products

Microsoft Visual Studio 2019 version 16.11 (includes 16.0 - 16.10)
Microsoft Visual Studio 2022 version 17.12
Microsoft Visual Studio 2022 version 17.14

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21637
https://nvd.nist.gov/vuln/detail/CVE-2026-21637

Published: 2026-04-14 · Source: Microsoft · Feed updated: 2026-08-04

This high severity vulnerability with a CVSS score of 7.5 was published on 2026-04-14 via Microsoft. Affected: Microsoft Visual Studio 2019 version 16.11 (includes 16.0 - 16.10), Microsoft Visual Studio 2022 version 17.12, Microsoft Visual Studio 2022 version 17.14.

vulnfeed aggregates 9166 vulnerabilities from NVD, CISA KEV, Ubuntu, Debian, Red Hat, Kubernetes, Exploit-DB, OSS-Security, GitHub and OpenStack — updated every 4 hours.