How severe is CVE-2018-8302?

CVE-2018-8302 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-8302 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 26% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-8302?

CVE-2018-8302 primarily affects Microsoft Exchange Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-8302?

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

When was CVE-2018-8302 published?

CVE-2018-8302 was published on 2018-08-15 and last updated on 2026-06-17.

CVE-2018-8302

CVE-2018-8302 is a critical-severity vulnerability in Microsoft Exchange Server with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 26% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 26% (98th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Microsoft Exchange Server
Published: 2018-08-15
Last modified: 2026-06-17

Description

A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka "Microsoft Exchange Memory Corruption Vulnerability." This affects Microsoft Exchange Server.

Frequently asked questions

What is CVE-2018-8302?: A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka "Microsoft Exchange Memory Corruption Vulnerability." This affects Microsoft Exchange Server.
How severe is CVE-2018-8302?: CVE-2018-8302 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-8302 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 26% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-8302?: CVE-2018-8302 primarily affects Microsoft Exchange Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-8302?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2018-8302 published?: CVE-2018-8302 was published on 2018-08-15 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:microsoft:exchange_server:2010:sp3:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_20:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_21:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_10:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_9:*:*:*:*:*:*

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