SB2026061826 - Multiple vulnerabilities in Zimbra Collaboration

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Main Vulnerability Database SB2026061826

SB2026061826 - Multiple vulnerabilities in Zimbra Collaboration

Published: June 18, 2026

Security Bulletin ID SB2026061826
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 6
Exploitation vector Remote access
Highest impact Information disclosure

Breakdown by Severity

Medium 67% Low 33%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 6 vulnerabilities.


1) Improper Authorization (CVE-ID: N/A)

CWE-ID: CWE-285 - Improper Authorization

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to send emails impersonating other users.

The vulnerability exists due to improper access control in delegated send handling when processing delegated send requests. A remote user can send a crafted request to send emails impersonating other users.


2) Cross-site scripting (CVE-ID: N/A)

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

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to execute script content in the victim's browser.

The vulnerability exists due to cross-site scripting in the Classic UI attachment preview when previewing malicious email attachments. A remote attacker can send a crafted email attachment to execute script content in the victim's browser.

User interaction is required to preview a crafted attachment.


3) Path traversal (CVE-ID: N/A)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to disclose local file contents.

The vulnerability exists due to path traversal in the Briefcase document feature when processing the packages parameter. A remote user can supply a crafted packages parameter to disclose local file contents.


4) Path traversal (CVE-ID: N/A)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to disclose local file contents.

The vulnerability exists due to path traversal in the Classic UI when processing an input parameter. A remote attacker can supply a crafted input parameter to disclose local file contents.


5) Cross-site request forgery (CVE-ID: N/A)

CWE-ID: CWE-352 - Cross-Site Request Forgery (CSRF)

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to perform unauthorized actions on behalf of an authenticated user.

The vulnerability exists due to cross-site request forgery in the EWS endpoint when handling crafted cross-site requests. A remote attacker can cause the victim's browser to send a crafted request to perform unauthorized actions on behalf of an authenticated user.

User interaction is required while the victim has an active authenticated session.


6) Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) (CVE-ID: N/A)

CWE-ID: CWE-338 - Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to brute-force the JWT signing secret offline.

The vulnerability exists due to use of a weak pseudo-random number generator in zimbraDocumentEditingJwtSecret generation when creating the JWT signing secret. A remote attacker can perform offline guessing attacks to brute-force the JWT signing secret.


Remediation

Install update from vendor's website.

References