Which products and versions are affected by CVE-2024-50599?

Affected: Zimbra Collaboration Suite (Synacor) versions 8.8.15, 8.8.15-p1, 8.8.15-p10, 8.8.15-p11, 8.8.15-p12, 8.8.15-p13, 8.8.15-p14, 8.8.15-p15. The full list is in the CVE brief.

Is CVE-2024-50599 being exploited in the wild?

It is exploited in the wild, listed in Industry KEV feed since Sep 4, 2024.

Is CVE-2024-50599 in the CISA KEV catalog?

No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.

Is there a public exploit for CVE-2024-50599?

No public exploit code is known.

Is there a fix for CVE-2024-50599?

No fixed version is listed yet; check the vendor advisory for mitigations.

How urgently should CVE-2024-50599 be patched?

Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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Vulnerability Intelligence

CVE-2024-50599

MediumExploited

A reflected Cross-Site Scripting (XSS) vulnerability has been identified in Zimbra Collaboration Suite (ZCS) 8.8.15, affecting one of the webmail calendar endpoints.

Published Nov 7, 2024 · Updated Aug 12, 2026

Key Facts

Patch immediately

CVE-2024-50599 is a medium-severity vulnerability (CVSS 6.1 v3.1) affecting Zimbra Collaboration Suite (Synacor).
It is exploited in the wild, listed in Industry KEV feed since Sep 4, 2024. No public exploit code is known.
EPSS estimates a 64% probability of exploitation in the next 30 days.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v3.1

6.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS (30-day exploit likelihood)

64%

Higher than 99.2% of all scored CVEs

Exploited in the wild

Yes

1 catalog listing

Public exploit code

None known

Get the full CVE-2024-50599 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

A reflected Cross-Site Scripting (XSS) vulnerability has been identified in Zimbra Collaboration Suite (ZCS) 8.8.15, affecting one of the webmail calendar endpoints. This arises from improper handling of user-supplied input, allowing an attacker to inject malicious code that is reflected back in the HTML response.

Known-Exploited Catalog Listings

Catalog	Added	Remediation due	Ransomware use
Industry KEV feed	Sep 4, 2024	n/a	Not reported

Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Affected Products

47 affected entries in total

Product	Affected versions	Fixed in
Zimbra Collaboration SuiteSynacor	8.8.15, 8.8.15-p1, 8.8.15-p10, 8.8.15-p11, 8.8.15-p12, 8.8.15-p13, 8.8.15-p14, 8.8.15-p15	n/a

Timeline

Added to Industry KEV feed
Sep 4, 2024
Publicly disclosed
Nov 7, 2024
Last updated
Aug 12, 2026

Weakness Type

CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

References

FAQ

Common Questions.

A reflected Cross-Site Scripting (XSS) vulnerability has been identified in Zimbra Collaboration Suite (ZCS) 8.8.15, affecting one of the webmail calendar endpoints.
Affected: Zimbra Collaboration Suite (Synacor) versions 8.8.15, 8.8.15-p1, 8.8.15-p10, 8.8.15-p11, 8.8.15-p12, 8.8.15-p13, 8.8.15-p14, 8.8.15-p15. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Sep 4, 2024.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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