How severe is CVE-2026-88859?

CVE-2026-88859 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-88859 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-88859?

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

When was CVE-2026-88859 published?

CVE-2026-88859 was published on 2026-09-10.

CVE-2026-88859

CVE-2026-88859 is a medium-severity vulnerability with a CVSS 3.x base score of 6.3. 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-84.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-84
Published: 2026-09-10
Last modified: 2026-09-10

Description

A flaw was found in Evolution. A remote attacker can exploit this vulnerability by sending a specially crafted HTML email containing a spoofed vCard control. When a victim clicks on this control, Evolution's trusted JavaScript handler incorrectly assigns an attacker-controlled JavaScript URL to an iframe's source. This action leads to arbitrary JavaScript execution within the mail-viewing context, effectively bypassing the security measures designed to prevent script execution in email content.

Frequently asked questions

What is CVE-2026-88859?: A flaw was found in Evolution. A remote attacker can exploit this vulnerability by sending a specially crafted HTML email containing a spoofed vCard control. When a victim clicks on this control, Evolution's trusted JavaScript handler incorrectly assigns an attacker-controlled JavaScript URL to an iframe's source. This action leads to arbitrary JavaScript execution within the mail-viewing context, effectively bypassing the security measures designed to prevent script execution in email content.
How severe is CVE-2026-88859?: CVE-2026-88859 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-88859 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-88859?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-88859 published?: CVE-2026-88859 was published on 2026-09-10.

References

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