Known vulnerability record

CVE-2026-45659

Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerability

Stable IDcve:CVE-2026-45659Source record date2026-08-11Human reviewNot recordedProvenanceSource-linked CVE, KEV, and EPSS signals

Summary

Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerability

Microsoft SharePoint Server contains a deserialization of untrusted data vulnerability which allows an authorized attacker to execute code over a network.

Vulns.co field classification

Interpreter injection on enterprise application

Derived analysis: these labels are inferred from the source title, product, and summary. They are not vendor, CVE, CISA, or FIRST classifications.

Failure classInterpreter injection

Product laneEnterprise application

Attention stateKnown exploited with confirmed ransomware use

Hunter pivot

Locate each parser boundary before choosing a probe. Vary one delimiter or encoding at a time, use non-destructive canaries, and distinguish interpreter behavior from generic errors.

Signals

Keep the signals separate

CVSS severityhighScore 8.8 · source microsoft

EPSS probability76.1%Probability of exploitation in the next 30 days; not severity

CISA KEVKnown exploitedAdded 2026-07-01

Ransomware useknownPreserved as known / unknown, not a truthy default

Research boundary

Confirm the product before the behavior.

Match the exact product, build, deployment mode, and exposed component.
Read the vendor advisory and current program policy.
Choose one non-destructive discriminator with an explicit negative control.
Stop at the first sufficient proof. A CVE match is context, not permission.

Timeline

Dates and provenance

CVE published: 2026-05-22
CVE modified: 2026-08-11
KEV date added: 2026-07-01
Dataset fetched: 2026-08-25T13:17:11.442Z

Sources

Original records

Version history: normalized permanent page created 2026-08-20. Machine-enriched fields remain source-attributed.