CVE-2026-23666 | .NET Framework Denial of Service Vulnerability

Improper input validation in .NET Framework allows an unauthorized attacker to deny service over a network.

Published: 2026-04-14 Last update: 2026-05-07 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-23666 is rated Moderate Risk (41.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.13%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-23666

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-30 0.15% 0.13% -0.02%
2 2026-05-25 0.08% 0.15% +0.07%
3 2026-04-15 — 0.08% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-23666

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-23666

OS Trackers for CVE-2026-23666

vendor priority summary link
redhat high — https://access.redhat.com/security/cve/CVE-2026-23666

Affected software / configurations for CVE-2026-23666

Vendor Product Version Raw CPE
microsoft .net_framework 3.5 cpe:2.3:a:microsoft:.net_framework:3.5:-:*:*:*:*:*:*
microsoft .net_framework 4.7.2 cpe:2.3:a:microsoft:.net_framework:4.7.2:*:*:*:*:*:*:*
microsoft .net_framework 4.8 cpe:2.3:a:microsoft:.net_framework:4.8:*:*:*:*:*:*:*
microsoft .net_framework 4.8.1 cpe:2.3:a:microsoft:.net_framework:4.8.1:*:*:*:*:*:*:*
microsoft .net_framework 4.6.2 cpe:2.3:a:microsoft:.net_framework:4.6.2:*:*:*:*:*:*:*
microsoft .net_framework 4.7 cpe:2.3:a:microsoft:.net_framework:4.7:*:*:*:*:*:*:*
microsoft .net_framework 4.7.1 cpe:2.3:a:microsoft:.net_framework:4.7.1:*:*:*:*:*:*:*

References for CVE-2026-23666

cvelogic Threat Intelligence