Sunday, October 18, 2026

Critical Zimbra Flaws Allow Attackers to Gain Unauthorized Access to Sensitive Data

Serious vulnerabilities in Zimbra Collaboration Suite (ZCS), a popular enterprise email and collaboration platform, have raised alarm in the cybersecurity community.

Security researchers have identified several critical flaws that allow attackers to access sensitive data and compromise user accounts.

With millions of businesses relying on Zimbra for email services, these vulnerabilities pose significant risks.

Key Vulnerabilities Disclosed

The newly disclosed vulnerabilities include an array of attack vectors that exploit Zimbra’s web client, SOAP endpoints, and integrated API services. Among the most severe are:

  1. SQL Injection in ZimbraSyncService (CVE-2025-25064)
    A critical flaw in the ZimbraSyncService SOAP endpoint allows attackers to exploit SQL injection vulnerabilities. This could lead to unauthorized data exfiltration or manipulation of backend database records.
  2. SSRF in RSS Feed Parser (CVE-2025-25065)
    A Server-Side Request Forgery (SSRF) vulnerability in Zimbra’s RSS feed parser allows attackers to redirect requests to internal network endpoints. Exploiting this vulnerability could open avenues for lateral movement within corporate networks.
  3. Cross-Site Scripting (XSS) in Classic Web Client (CVE-2024-45516)
    A stored XSS vulnerability in the Zimbra Classic Web Client could enable attackers to inject malicious scripts into user sessions, leading to potential account compromise or unauthorized actions performed on behalf of users.
  4. CSRF in GraphQL Endpoints
    Critical GraphQL API endpoints were found vulnerable to Cross-Site Request Forgery (CSRF) attacks, enabling attackers to perform unauthorized API operations without valid authentication tokens.

These vulnerabilities could lead to a range of critical issues, including data theft, unauthorized account access, and disruption of services.

Enterprises using vulnerable Zimbra versions are particularly at risk as attackers actively exploit such issues to gain access to sensitive corporate information.

Recommended Actions

Zimbra has released patches addressing the vulnerabilities in its latest updates:

  • Zimbra 9.0.0 Patch 44
  • Zimbra 10.0.13 & 10.1.5

Organizations using older versions are urged to upgrade immediately. Failure to do so could leave systems exposed to attack.

The recent vulnerabilities underscore the importance of prompt patch management and robust security practices.

Organizations using Zimbra should act urgently to secure their systems, as attackers often exploit publicly disclosed vulnerabilities before widespread patches are applied.

Regular software updates and an emphasis on proactive threat monitoring remain vital in preventing unauthorized access to sensitive data.

Are you from SOC/DFIR Team? - Join 500,000+ Researchers to Analyze Cyber Threats with ANY.RUN Sandbox - Try for Free

Divya
Divya
Divya is a Senior Journalist at GBhackers covering Cyber Attacks, Threats, Breaches, Vulnerabilities and other happenings in the cyber world.

Hot this week

How To Access Dark Web Anonymously and know its Secretive and Mysterious Activities

What is Deep Web The deep web, invisible web, or...

How to Build and Run a Security Operations Center (SOC Guide) – 2023

Today’s Cyber security operations center (CSOC) should have everything...

Russian Hackers Bypass EDR to Deliver a Weaponized TeamViewer Component

TeamViewer's popularity and remote access capabilities make it an...

Web Server Penetration Testing Checklist – 2026

Web server pentesting is performed under three significant categories: identity,...

ATM Penetration Testing – Advanced Testing Methods to Find The Vulnerabilities

ATM Penetration testing, Hackers have found different approaches to...

Hackers Use ConnectWise SkyKick Credentials to Access Microsoft 365, Halting Cloud Backups

Attackers abused compromised ConnectWise Cloud Backup credentials to access...

Anthropic’s Claude AI Uncovers Origins of NSA-Provided Cryptographic Keys After 25 Years

Anthropic says an internal Claude research model reconstructed how...

OpenBSD Kernel Flaw Dating Back 37 Years Enables Local Privilege Escalation to Root

A newly disclosed OpenBSD kernel exploitation chain combines a...

GhostAction Hackers Hide Credential-Stealing Malware in Fake Font Files Across 94 GitHub Repositories

GhostAction attackers have expanded their GitHub credential theft campaign...

SideCopy Hackers Target Indian Organizations With ReverseRAT Malware to Steal Data

Indian authorities have warned that SideCopy hackers are targeting...

New GhostBat Android Malware Targets 60 Banking and UPI Apps to Steal PINs

A new GhostBat RAT variant targets 60 Android financial...

New ROMULUS Malware Platform Uses Six Servers to Deliver Multiple Malicious Payloads

ROMULUS, a shared ClickFix delivery platform operating across six...

Related Articles

Recent News