How severe is CVE-2020-11737?

CVE-2020-11737 has a CVSS 3.x base score of 6.1, 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 none.

Is CVE-2020-11737 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-11737?

CVE-2020-11737 affects Zimbra. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-11737?

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

When was CVE-2020-11737 published?

CVE-2020-11737 was published on 2020-05-05 and last updated on 2026-06-17.

CVE-2020-11737

CVE-2020-11737 is a medium-severity vulnerability in Zimbra with a CVSS 3.x base score of 6.1. 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 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 2% (75th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Zimbra
Published: 2020-05-05
Last modified: 2026-06-17

Description

A cross-site scripting (XSS) vulnerability in Web Client in Zimbra 9.0 allows a remote attacker to craft links in an E-Mail message or calendar invite to execute arbitrary JavaScript. The attack requires an A element containing an href attribute with a "www" substring (including the quotes) followed immediately by a DOM event listener such as onmouseover. This is fixed in 9.0.0 Patch 2.

Frequently asked questions

What is CVE-2020-11737?: A cross-site scripting (XSS) vulnerability in Web Client in Zimbra 9.0 allows a remote attacker to craft links in an E-Mail message or calendar invite to execute arbitrary JavaScript. The attack requires an A element containing an href attribute with a "www" substring (including the quotes) followed immediately by a DOM event listener such as onmouseover. This is fixed in 9.0.0 Patch 2.
How severe is CVE-2020-11737?: CVE-2020-11737 has a CVSS 3.x base score of 6.1, 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 none.
Is CVE-2020-11737 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-11737?: CVE-2020-11737 affects Zimbra. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-11737?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-11737 published?: CVE-2020-11737 was published on 2020-05-05 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:zimbra:zimbra:9.0.0:*:*:*:*:*:*:*

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