CVE-2026-93638: Zimbra Collaboration Suite · Cross-site Scripting
Affects Zimbra Collaboration SuiteSource CVE Database V5
Not known to be exploited · CVSS 6.1 Medium.
Data as of 26 Oct 2026, 14:00 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| ZimbraZimbra Collaboration Suite | Affected
| Fixed in– |
AI-suggested
Until a fix is available, users should be cautious about opening unsolicited or suspicious relogin URLs.
Description
CVE-2026-93638 is a reflected cross-site scripting (XSS) vulnerability in the login page of Zimbra Collaboration Suite (ZCS) versions up to 10.1.17. It arises from improper neutralization of the zrememberme parameter, which is inserted into a hidden input attribute without HTML encoding during a two-factor error display. An unauthenticated attacker can craft a relogin URL that executes arbitrary JavaScript in the victim's browser under the legitimate Zimbra origin, potentially capturing credentials via a fake login form. The attack logs out any existing session before rendering, so mailbox access from the prior session is not inherited. The vulnerability has a CVSS score of 6.1 (medium severity).