How severe is CVE-2026-45501?

CVE-2026-45501 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-45501 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-45501?

CVE-2026-45501 primarily affects Microsoft Exchange Server. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-45501?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-45501 have an EU (EUVD) identifier?

Yes. CVE-2026-45501 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35677.

When was CVE-2026-45501 published?

CVE-2026-45501 was published on 2026-06-09 and last updated on 2026-06-17.

CVE-2026-45501

CVE-2026-45501 is a medium-severity vulnerability in Microsoft Exchange Server with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (23rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-35677
Weakness: CWE-79
Affected product: Microsoft Exchange Server
Published: 2026-06-09
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-45501?: 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.
How severe is CVE-2026-45501?: CVE-2026-45501 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-45501 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-45501?: CVE-2026-45501 primarily affects Microsoft Exchange Server. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-45501?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-45501 have an EU (EUVD) identifier?: Yes. CVE-2026-45501 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35677.
When was CVE-2026-45501 published?: CVE-2026-45501 was published on 2026-06-09 and last updated on 2026-06-17.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45501

Affected products (4)

cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_23:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_14:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_15:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server_subscription_edition:*:*:*:*:*:*:*:*

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