CVE-2026-93638 Details
A reflected cross-site scripting vulnerability in the login page of Zimbra Collaboration Suite (ZCS) allows an unauthenticated attacker to execute JavaScript through the zrememberme parameter. A crafted relogin URL selects a two-factor error display that inserts the parameter into a hidden input attribute without HTML encoding. A victim who opens the URL receives attacker-controlled script and page content under the legitimate Zimbra origin, allowing credential capture through a replacement login form. The relogin path logs out an existing session before rendering the payload, so the demonstrated attack does not inherit that session's mailbox access. ZCS 10.1.16 and 10.1.17 are affected.
View at NVD
Exploit prediction scoring system (EPSS) score for CVE-2026-93638
EPSS (Exploit Prediction Scoring System): EPSS predicts the likelihood that a vulnerability will be exploited in the wild. A higher percentage means a greater chance of an exploit occurring. The EPSS model produces a probability score between 0 and 1 (0 and 100%).
0.3 Probability of exploitation activity being observed over the next 30 days (22nd percentile)
CVSS score for CVE-2026-93638
CVSS (Common Vulnerability Scoring System): An open framework owned and managed by FIRST.Org, Inc. that assigns a numerical score from 0 to 10 to software vulnerabilities to indicate their severity.
6.1 Medium
Products affected by CVE-2026-93638
Zimbra Collaboration Suite 8.6.0
Zimbra Collaboration Suite 8.7.11
Zimbra Collaboration Suite 8.8.10
Zimbra Collaboration Suite 8.8.11
Zimbra Collaboration Suite 8.8.12
DVE Score by Bitsight AI
DVE scores complement traditional static scoring systems like CVSS with Bitsight AI powered real-time threat intelligence and underground cyber criminal activity so that security teams can reduce alert fatigue and focus on vulnerabilities most likely to be exploited.
Low
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CVE-2026-93638 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
US 66 9.12%
ID 54 7.46%
BR 54 7.46%
VN 38 5.25%
CA 31 4.28%
DE 29 4.01%
FR 28 3.87%
IN 25 3.45%
TR 23 3.18%
IT 22 3.04%

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CVE-2026-93638 Industry Footprint

Top 10 Identified Industries

*Service provider organizations (typically Technology and Telecommunications) are disproportionally represented in the results given their upstream ownership of end-user infrastructure. See our FAQs.

Industry* Observations Percentage
Technology 178 46.72%
Telecommunications 162 42.52%
Government/Politics 12 3.15%
Business Services 7 1.84%
Education 5 1.31%
Finance 4 1.05%
Food Production 3 0.79%
Transportation 2 0.52%
Engineering 2 0.52%
Manufacturing 2 0.52%

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