Threat Intelligence / CVE / CVE-2026-33115

CVE-2026-33115 — Microsoft Visual Studio

CVSS v3.1 8.1 (HIGH) · EPSS 0.0% (higher than 22.4% of all scored CVEs) · Priority 4.9/10 · Published 2026-04-14

As of 2026-04-14, CVE-2026-33115 is a HIGH-severity vulnerability in Microsoft Visual Studio, CVSS v3.1 8.1, EPSS 0.0% (22.4th percentile). Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2026-33115, most recently “Microsoft April 2026 Patch Tuesday — 163 CVEs / 88 Advisories (CVE-2026-32201 SharePoint Zero-Day Exploited In-The-Wild, CVE-2026-33825 Defender EoP Public PoC, CVE-2026-33824 IKE RCE CVSS 9.8, CVE-2026-33827 TCP/IP Wormable RCE)”.

Last updated: 2026-04-14

What is CVE-2026-33115?

A remote code execution vulnerability exists in .NET and Visual Studio due to unsafe deserialization in the BinaryFormatter fallback path. An attacker who successfully exploits this vulnerability could execute arbitrary code on the target system. The vulnerability was disclosed as part of the Microsoft April 2026 Patch Tuesday release, which remediated 167 vulnerabilities across Windows, Office, SharePoint, .NET, Defender, Active Directory, Remote Desktop, Azure, Hyper-V, and supporting components. This CVE was rated Critical severity with a CVSS 8.1 base score. Exploitation requires an attacker to craft a malicious serialized object that triggers the BinaryFormatter deserialization path, which can lead to full code execution in the context of the application.

The record classifies CVE-2026-33115 under weakness class CWE-502. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 151 days ago.

Severity and exploitation probability

CVSS v3.1 base score
8.1 — HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (FIRST)
0.0% probability of exploitation in the next 30 days, higher than 22.4% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
4.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-04-14

Is CVE-2026-33115 being exploited?

It currently carries a trending score of 11 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-33115

The record marks a vendor fix as available for CVE-2026-33115. Patch reference: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33115. Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33115. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2026-33115

2 tracked threats in the Threadlinqs corpus reference CVE-2026-33115, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Seeded from threat-derived and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

Full detection coverage & IOCs for threats exploiting CVE-2026-33115 are available via the Threadlinqs MCP server (Purple tier). View plans →

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