How severe is CVE-2020-13653?

CVE-2020-13653 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-2020-13653 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-13653?

CVE-2020-13653 primarily affects Synacor Zimbra Collaboration Suite. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-13653?

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

When was CVE-2020-13653 published?

CVE-2020-13653 was published on 2020-07-02 and last updated on 2026-06-17.

CVE-2020-13653

CVE-2020-13653 is a medium-severity vulnerability in Synacor Zimbra Collaboration Suite 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: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Synacor Zimbra Collaboration Suite
Published: 2020-07-02
Last modified: 2026-06-17

Description

An XSS vulnerability exists in the Webmail component of Zimbra Collaboration Suite before 8.8.15 Patch 11. It allows an attacker to inject executable JavaScript into the account name of a user's profile. The injected code can be reflected and executed when changing an e-mail signature.

Frequently asked questions

What is CVE-2020-13653?: An XSS vulnerability exists in the Webmail component of Zimbra Collaboration Suite before 8.8.15 Patch 11. It allows an attacker to inject executable JavaScript into the account name of a user's profile. The injected code can be reflected and executed when changing an e-mail signature.
How severe is CVE-2020-13653?: CVE-2020-13653 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-2020-13653 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-13653?: CVE-2020-13653 primarily affects Synacor Zimbra Collaboration Suite. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-13653?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-13653 published?: CVE-2020-13653 was published on 2020-07-02 and last updated on 2026-06-17.

References

Affected products (12)

cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*
cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:-:*:*:*:*:*:*
cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p1:*:*:*:*:*:*
cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p10:*:*:*:*:*:*
cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p2:*:*:*:*:*:*
cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p3:*:*:*:*:*:*
cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p4:*:*:*:*:*:*
cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p5:*:*:*:*:*:*
cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p6:*:*:*:*:*:*
cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p7:*:*:*:*:*:*
cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p8:*:*:*:*:*:*
cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p9:*:*:*:*:*:*

More vulnerabilities in Synacor Zimbra Collaboration Suite

CVE-2024-45519 — Critical (CVSS 10.0): The postjournal service in Zimbra Collaboration (ZCS) before 8.8.15 Patch 46, 9 before 9.0.0 Patch 41, 10 before…
CVE-2022-41352 — Critical (CVSS 9.8): An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0. An attacker can upload arbitrary files through…
CVE-2022-37042 — Critical (CVSS 9.8): Zimbra Collaboration Suite (ZCS) 8.8.15 and 9.0 has mboximport functionality that receives a ZIP archive and extracts…
CVE-2020-7796 — Critical (CVSS 9.8): Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7 allows SSRF when WebEx zimlet is installed and zimlet JSP is…
CVE-2019-9670 — Critical (CVSS 9.8): mailboxd component in Synacor Zimbra Collaboration Suite 8.7.x before 8.7.11p10 has an XML External Entity injection…
CVE-2019-6980 — Critical (CVSS 9.8): Synacor Zimbra Collaboration Suite 8.7.x through 8.8.11 allows insecure object deserialization in the IMAP component.

All CVEs affecting Synacor Zimbra Collaboration Suite →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →