April 2026 Patch TuesdayMSRC-2026-04-developer-tools-release-notesNormal patch window

Microsoft · MSRC-2026-04-developer-tools-release-notes

Linked CVE review

Deploy Microsoft Developer Tools update for PowerShell 7.5

Linked CVEs: 2
Confirmed exploited: 0
PoC or lab evidence: 0
Maximum CVSS: 7.8

Evidence is kept separate

Confirmed exploitation, public exploit material, EPSS probability and CVSS severity answer different questions. “No confirmation recorded” means the checked sources do not currently confirm exploitation. It is not proof that exploitation has not occurred.

2 of 2 linked CVEs shown

Confirmed exploitedCVSS above 9.0

CVE and description	Severity	Exploit reality	Forecast and access	Remediation
CVE-2026-26171 Scheduled assessment .NET Denial of Service Vulnerability A flaw was found in .NET. A remote attacker could exploit a vulnerability related to unsafe transforms in EncryptedXml. This could lead to a Denial of Service (DoS), making the service unavailable, and a bypass of security features.	7.5 · CVSS 3.1 · HighSource: CNA	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 2.26% · 82.5th percentileForecast date: 2026-10-07NETWORK · LOW complexity · NONE privileges · NONE user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Patch available. RHSA-2026:13281: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)
CVE-2026-26143 Scheduled assessment Microsoft PowerShell Security Feature Bypass Vulnerability Improper input validation in Microsoft PowerShell allows an unauthorized attacker to bypass a security feature locally.	7.8 · CVSS 3.1 · HighSource: CNA	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 0.47% · 38.4th percentileForecast date: 2026-10-07LOCAL · LOW complexity · NONE privileges · REQUIRED user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Mitigation available. No fixed version is explicitly recorded in the structured CVE data.