How severe is CVE-2026-42893?

CVE-2026-42893 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-42893 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-42893?

CVE-2026-42893 affects Microsoft Outlook. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-42893?

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.

Does CVE-2026-42893 have an EU (EUVD) identifier?

Yes. CVE-2026-42893 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29716.

When was CVE-2026-42893 published?

CVE-2026-42893 was published on 2026-05-12 and last updated on 2026-06-17.

CVE-2026-42893

CVE-2026-42893 is a high-severity vulnerability in Microsoft Outlook with a CVSS 3.x base score of 7.4. 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-77.

Key facts

Severity: High (CVSS 3.x base score 7.4)
EPSS exploit prediction: 0% (32nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-29716
Weakness: CWE-77
Affected product: Microsoft Outlook
Published: 2026-05-12
Last modified: 2026-06-17

Description

Improper neutralization of special elements used in a command ('command injection') in M365 Copilot allows an unauthorized attacker to perform tampering over a network.

Frequently asked questions

What is CVE-2026-42893?: Improper neutralization of special elements used in a command ('command injection') in M365 Copilot allows an unauthorized attacker to perform tampering over a network.
How severe is CVE-2026-42893?: CVE-2026-42893 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-42893 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-42893?: CVE-2026-42893 affects Microsoft Outlook. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-42893?: 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.
Does CVE-2026-42893 have an EU (EUVD) identifier?: Yes. CVE-2026-42893 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29716.
When was CVE-2026-42893 published?: CVE-2026-42893 was published on 2026-05-12 and last updated on 2026-06-17.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42893

Affected products (1)

cpe:2.3:a:microsoft:outlook:*:*:*:*:*:iphone_os:*:*

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