Highest advisory severityHigh 2 vendors · 2 advisories

CVE-2026-97801: .NET Framework Tampering Vulnerability

Not in the CISA KEV catalog. High advisory severity (CVSS 7.5, MS Server).

Compare the source-linked records below. Ratings and product/version details belong to each advisory; they are not a single CVE-wide score or proof that every listed product is affected. How VulniPulse collects and checks evidence.

NVD detail CVE.org

CVE-2026-97801 key facts

CISA KEV: Not listed (catalog checked Nov 6, 2026)
Highest advisory severity: High
CVSS base score: 7.5 (MS Server)
Weakness: CWE-1287
Fixed releases: MS Server: KB5127689 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0), KB5127690 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0), KB5127691 (build 4.8.9363.0), KB5127692 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0), KB5127693 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0), KB5127694 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.10008.0) and 2 more in the advisory
Vendor advisories: 2 from MS Server, Red Hat
VulniPulse record: Published Oct 13, 2026 · Updated Oct 23, 2026

Scores, vectors, weaknesses and fixed releases are quoted from vendor advisories that cover only CVE-2026-97801; bulletin-wide values are not repeated here.

Is CVE-2026-97801 exploited?

No exploitation is reported in the sources VulniPulse tracks: CVE-2026-97801 is not in the CISA KEV catalog (checked Nov 6, 2026) and no tracked advisory for it reports exploitation. That is not proof the vulnerability cannot be exploited.

How do I fix CVE-2026-97801?

Upgrade to a fixed release named by the vendor:

MS Server: KB5127689 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0), KB5127690 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0), KB5127691 (build 4.8.9363.0), KB5127692 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0), KB5127693 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0), KB5127694 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.10008.0)

Install the applicable security update for your platform: KB5127689, KB5127690, KB5127691, KB5127692, KB5127693, KB5127694 (see the Microsoft Update Catalog). (MS Server)

Get an email when Microsoft publishes the next one.

See Microsoft's last 90 days of advisories first. Then choose one product with live alerts free for life, or a free month of real-time alerts on everything with the severity, the fixed version and the vendor's link (card needed, then US$15/month; we email you before the first charge).

Alert me about Microsoft

Vendor advisory comparison

MS Server

1 advisory

Advisory severityHigh7.5
High [CVE-2026-97801] .NET Framework Tampering Vulnerability
CVE-2026-97801Source published Oct 13, 2026
.NET Framework Tampering Vulnerability Affected products named by the advisory: Microsoft.NET Framework 3.5 AND 4.8.1 on Windows Server 2025; Microsoft.NET Framework 3.5 AND 4.8.1 on Windows Server 2022; Microsoft.NET Framework 3.5 on Windows Server 2012; Microsoft.NET Framework 3.5 on Windows Server 2012 R2; and 4 more. Affected products named by the advisory: Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016; Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2019; Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2019; Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2022.
Affected products in this advisory
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2025
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2022
Microsoft .NET Framework 3.5 on Windows Server 2012 R2
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016
3 more entries in the full advisory.
Source-reported affected versions
Affected-version details not available in this record.
Source-reported fixed versions
KB5127689 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0)
KB5127690 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0)
KB5127691 (build 4.8.9363.0)
KB5127692 (build 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0)
4 more entries in the full advisory.
Mitigation guidance
Install the applicable security update for your platform: KB5127689, KB5127690, KB5127691, KB5127692, KB5127693, KB5127694 (see the Microsoft Update Catalog).
Full advisory and evidence Open source bulletin

Red Hat

1 advisory

Advisory severityHigh
High [CVE-2026-97801] .NET Framework: Data tampering via improper input validation
CVE-2026-97801Source published Oct 13, 2026Source updated Oct 13, 2026
.NET Framework: Data tampering via improper input validation. Red Hat rates this important. Weakness: CWE-1287. Affected product named by the advisory: Red Hat Hardened Images.
Related products — impact not confirmed
Red Hat Hardened Images
Source-reported affected versions
Affected-version details not available in this record.
Source-reported fixed versions
No fixed-version detail extracted. This does not mean no fix exists.
Mitigation guidance
No mitigation guidance extracted; consult the source.
Full advisory and evidence Open source bulletin

All MS Server advisories

Follow CVE-2026-97801 in the free weekly digest

Every Monday: whether it was added to CISA KEV, reported exploited, got a fix or changed severity, plus the week's critical and high advisories.

Browse the latest tracked CVEs or the CVEs listed in CISA KEV.

iPhone and Android apps · New on the App Store

Get alerts for new CVEs on your phone.

Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.

Matching phone alertsOptional email delivery

Get CVE alerts on Android See app features