How severe is CVE-2026-65815?

CVE-2026-65815 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-65815 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-65815?

CVE-2026-65815 affects Microsoft Dynamics 365. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-65815?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-65815 published?

CVE-2026-65815 was published on 2026-08-11 and last updated on 2026-08-17.

CVE-2026-65815

CVE-2026-65815 is a high-severity vulnerability in Microsoft Dynamics 365 with a CVSS 3.x base score of 8.8. 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-502.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Microsoft Dynamics 365
Published: 2026-08-11
Last modified: 2026-08-17

Description

Deserialization of untrusted data in Microsoft Dynamics 365 (on-premises) allows an authorized attacker to execute code over a network.

Frequently asked questions

What is CVE-2026-65815?: Deserialization of untrusted data in Microsoft Dynamics 365 (on-premises) allows an authorized attacker to execute code over a network.
How severe is CVE-2026-65815?: CVE-2026-65815 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-65815 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-65815?: CVE-2026-65815 affects Microsoft Dynamics 365. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-65815?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-65815 published?: CVE-2026-65815 was published on 2026-08-11 and last updated on 2026-08-17.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65815

Affected products (1)

cpe:2.3:a:microsoft:dynamics_365:*:*:*:*:on-premises:*:*:*

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