CVE-2026-45500
Microsoft Exchange Server Spoofing Vulnerability
No known exploitation. EPSS puts it in the 32nd percentile. Fixed versions are out.
No public exploit knownFix5 products5 fixed builds listed below
e.g. OID 1.3.6.1.4.1.25623.1.0.119372
What to do
Find your product and version, then upgrade to the build on the right.
- Microsoft Exchange Server 2016 Cumulative Update 23Affected: ≥ 15.01.0.0, < 15.01.2507.071Upgrade to: 15.01.2507.071Stated by: CVE record
- Microsoft Exchange Server 2019 Cumulative Update 14Affected: ≥ 15.02.0.0, < 15.02.1544.043Upgrade to: 15.02.1544.043Stated by: CVE record
- Microsoft Exchange Server 2019 Cumulative Update 15Affected: ≥ 15.02.0.0, < 15.02.1748.048Upgrade to: 15.02.1748.048Stated by: CVE record
- Microsoft Exchange Server Subscription Edition RTMAffected: ≥ 15.02.0.0, < 15.02.2562.045Upgrade to: 15.02.2562.045Stated by: CVE record
- Microsoft Exchange Server Subscription EditionAffected: < 15.02.2562.043Upgrade to: 15.02.2562.043Stated by: NVD
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.4% chance of exploitation activity in the next 30 days, which ranks it in the 32nd percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
10 events over 49 days, from the signal feeds we watch.
- Patch availablerecord updated
- Patch availablerecord updated
- OpenVAS check added
- Patch availablerecord updated
- Publishedweakness classified, att&ck mapped
Affected products
- exchange serverOperating Systems / windows
- exchange server subscription editionEnterprise Software / itsm-monitoring
- Microsoft Exchange Server 2016 Cumulative Update 23Operating Systems
- Microsoft Exchange Server 2019 Cumulative Update 14Operating Systems / windows
- Microsoft Exchange Server 2019 Cumulative Update 15Enterprise Software / itsm-monitoring
- Microsoft Exchange Server Subscription Edition RTMEnterprise Software / itsm-monitoring
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Scored 6.1 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction RequiredA user must click a link, open a file, or perform some action
Scope
- Scope ChangedThe exploit can affect other components (e.g. sandbox escape, host compromise from VM)
Impact if exploited
- Confidentiality LowSome restricted information is disclosed, but limited in scope
- Integrity LowData modification is possible but limited in scope or consequence
- Availability NoneNo availability impact
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
Watch the software you run.
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We'll flag the next CVE, public exploit or patch for Exchange Server, not every advisory.
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