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CRITICAL severity

CVE-2026-77903 — Dataverse

CRITICAL

CVE-2026-77903 is a critical-severity (CVSS 9) CWE-290 vulnerability in microsoft dataverse. No vendor fix is recorded yet; mitigation options are listed below.

Authentication bypass by spoofing in Microsoft Dataverse allows an unauthorized attacker to elevate privileges over a network.

Published
Updated
Affected
1 product
Patched
See advisory
Exploits
None indexed
Exploitation data as of Oct 11, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-77903.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs29th percentile — riskier than 29% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-77903 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Description

Authentication bypass by spoofing in Microsoft Dataverse allows an unauthorized attacker to elevate privileges over a network.

Affected Products

1 product · 1 configurations
Application
dataversemicrosoft
all

Detection & mitigation playbook

Vendor / appliance
  1. Detect

    Inventory every microsoft dataverse deployment and check each version against the affected-products list above.

  2. Remediation status

    No patch has shipped for CVE-2026-77903 yet — track the microsoft dataverse advisory for a fixed release and apply the workarounds below in the meantime.

  3. Mitigate without a patch

    Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

Authentication bypass by spoofing in Microsoft Dataverse allows an unauthorized attacker to elevate privileges over a network.
O3 Security · Runtime Protection

Is CVE-2026-77903 being exploited in your environment?

Detect and block the exploit chain at execution, on systems you cannot patch yet.

CVE-2026-77903: Dataverse (Critical 9)