CVE-2026-21509
Is CVE-2026-21509 real, exploitable, or a false positive? Here's the community verdict.
signals
public sources
Confirmed exploited in the wild. Patch this first, regardless of the base score.
baseline read
auto · not a community verdict
Real — exploited in the wild
CISA confirms active exploitation. Treat scanner hits as true positives unless your specific version or config is unaffected.
Based on CISA KEV
Confirm or dispute →CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.
References
Published
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In your experience, is this finding real and exploitable?
awaiting field verdictsCurated baseline: TruePositive's read from public sources is Real & exploitable — a starting point, not a community verdict.
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Field notes & remediation
Verdicts are the quick signal. Notes are the evidence and fixes behind them.
- 0
Microsoft Office Security Feature Bypass Vulnerability — Microsoft Office contains a security feature bypass vulnerability in which reliance on untrusted inputs in a security decision in Microsoft Office could allow an unauthorized attacker to bypass a security feature locally. Some of the impacted product(s) could be end-of-life (EoL) and/or end-of-service (EoS). Users are advised to discontinue use and/or transition to a supported version. Listed in the CISA KEV catalog (added 2026-01-26) — confirmed exploited in the wild, not theoretical. FIRST EPSS puts the chance of exploitation in the next 30 days at ~72%. Treat it as real and prioritize remediation over triage.
- 0
Required action for Microsoft Office: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. CISA set a federal remediation due date of 2026-02-16. After patching, verify the vulnerable path is no longer reachable before closing the finding.
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Related CVEs
Same weakness: CWE-807.