CVE-2026-56191: Microsoft Exchange Online Tampering Vulnerability
This Microsoft advisory covers CVE-2026-56191 in Microsoft Exchange Online.
- CVE-2026-56191
Key facts
- Vendor rating
- Critical, CVSS 10
- CISA KEV
- Not listed (catalogue checked )
- Affected
- Microsoft Exchange Online -
- Source published
- Source revised
- Listed by VulniPulse
Compiled by VulniPulse from the linked sources. How records are collected and checked.
Affected products & platforms
Description
Improper authentication in Microsoft Exchange Online allows an unauthorized attacker to perform tampering over a network.
Text from the source record.
- Microsoft Exchange Online -
Official advisory · high-confidence parse· fetched ·verify at source
End-of-life dates for Microsoft Exchange Server
More Microsoft Server advisories
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Microsoft Server advisories, July 2026All Microsoft Server advisories
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