CVE-2021-35208

Name: CVE-2021-35208
Creator: NVD / NIST
Published: 2021-07-02T19:15:08.417+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.4/10EPSS 1.26%

Last modified Jun 17, 2026

CVE-2021-35208 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. An issue was discovered in ZmMailMsgView.js in the Calendar Invite component in Zimbra Collaboration Suite 8.8.x before 8.8.15 Patch 23. An attacker could place HTML containing executable JavaScript inside element attributes. EPSS estimates a 1.26% chance of exploitation in the next 30 days.

Description

An issue was discovered in ZmMailMsgView.js in the Calendar Invite component in Zimbra Collaboration Suite 8.8.x before 8.8.15 Patch 23. An attacker could place HTML containing executable JavaScript inside element attributes. This markup becomes unescaped, causing arbitrary markup to be injected into the document.

Metrics

CVSS 3.1

5.4/10

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

EPSS Probability

1.26%

65.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Zimbra	Collaboration	>= 8.8, < 8.8.15
Zimbra	Collaboration	8.8.15

References

https://blog.sonarsource.com/zimbra-webmail-compromise-via-emailExploit, Mitigation, Third Party Advisory
https://wiki.zimbra.com/wiki/Security_CenterRelease Notes, Vendor Advisory
https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P23Release Notes, Vendor Advisory
https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P16Release Notes, Vendor Advisory
https://wiki.zimbra.com/wiki/Zimbra_Security_AdvisoriesVendor Advisory
https://blog.sonarsource.com/zimbra-webmail-compromise-via-emailExploit, Mitigation, Third Party Advisory
https://wiki.zimbra.com/wiki/Security_CenterRelease Notes, Vendor Advisory
https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P23Release Notes, Vendor Advisory
https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P16Release Notes, Vendor Advisory
https://wiki.zimbra.com/wiki/Zimbra_Security_AdvisoriesVendor Advisory

Timeline

Published: Jul 2, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-35208?

How severe is CVE-2021-35208?

CVE-2021-35208 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 1.26% probability of exploitation in the next 30 days.

How do I fix CVE-2021-35208?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-35208?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST