Updated 4 h ago

Vulnerability database

Every flaw the U.S. government’s cybersecurity agency (CISA) has confirmed attackers are using, plus the new WordPress plugin and theme bugs published each day, sorted by what they mean for a small business. We refresh it twice a day. If you see something your website or office runs, tell us.

1,762exploited flaws on CISA’s list

34added in the last 30 days

324new WordPress flaws this week

390,007entries in the database

18 results

Aug 21, 2026Zimbra Collaboration Suite (ZCS) OS Command Injection VulnerabilityCVE-2026-73570 · Email & office · Synacor · reported by MITREExploitedHigh 8.9
Zimbra Collaboration Suite (ZCS) contains an OS command injection vulnerability which could allow an unauthenticated attacker to send specially crafted SMTP requests that may result in execution of arbitrary operating system commands as the Zimbra user.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Aug 21, 2026 (federal fix deadline Aug 24, 2026)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog wiki.zimbra.com wiki.zimbra.com
Apr 20, 2026Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting VulnerabilityCVE-2025-48700 · Email & office · Synacor · reported by MITREExploitedMedium 6.1
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability that could allow attackers to execute arbitrary JavaScript within the user's session, potentially leading to unauthorized access to sensitive information.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Apr 20, 2026 (federal fix deadline Apr 23, 2026)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog wiki.zimbra.com wiki.zimbra.com
Mar 18, 2026Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting VulnerabilityCVE-2025-66376 · Email & office · Synacor · reported by MITREExploitedHigh 7.2
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability in the Classic UI where attackers could abuse Cascading Style Sheets (CSS) @import directives in email HTML.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Mar 18, 2026 (federal fix deadline Apr 1, 2026)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog wiki.zimbra.com wiki.zimbra.com
Feb 17, 2026Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery VulnerabilityCVE-2020-7796 · Email & office · Synacor · reported by MITREExploitedCritical 9.8
Synacor Zimbra Collaboration Suite (ZCS) contains a server-side request forgery vulnerability if WebEx zimlet installed and zimlet JSP is enabled.
Product
Zimbra Collaboration Suite
On CISA’s list since
Feb 17, 2026 (federal fix deadline Mar 10, 2026)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog wiki.zimbra.com wiki.zimbra.com
Jan 22, 2026Synacor Zimbra Collaboration Suite (ZCS) PHP Remote File Inclusion VulnerabilityCVE-2025-68645 · Email & office · Synacor · reported by MITREExploitedHigh 8.8
Synacor Zimbra Collaboration Suite (ZCS) contains a PHP remote file inclusion vulnerability that could allow for remote attackers to craft requests to the /h/rest endpoint to influence internal request dispatching, allowing inclusion of arbitrary files from the WebRoot directory.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Jan 22, 2026 (federal fix deadline Feb 12, 2026)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog wiki.zimbra.com wiki.zimbra.com
Oct 7, 2025Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting VulnerabilityCVE-2025-27915 · Email & office · Synacor · reported by MITREExploitedMedium 5.4
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability that exists in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an e-mail message containing a malicious ICS entry, its embedded JavaScript executes via an ontoggle event inside a tag. This allows an attacker to run arbitrary JavaScript within the victim's session, potentially leading to unauthorized actions such as setting e-mail filters to redirect messages to an attacker-controlled address. As a result, an attacker can perform unauthorized actions on the victim's account, including e-mail redirection and data exfiltration.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Oct 7, 2025 (federal fix deadline Oct 28, 2025)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog wiki.zimbra.com wiki.zimbra.com
Jul 7, 2025Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery (SSRF) VulnerabilityCVE-2019-9621 · Email & office · Synacor · reported by MITREExploitedHigh 7.5
Synacor Zimbra Collaboration Suite (ZCS) contains a server-side request forgery (SSRF) vulnerability via the ProxyServlet component.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Jul 7, 2025 (federal fix deadline Jul 28, 2025)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog packetstormsecurity.com packetstormsecurity.com
May 19, 2025Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) VulnerabilityCVE-2024-27443 · Email & office · Synacor · reported by MITREExploitedMedium 6.1
Zimbra Collaboration contains a cross-site scripting (XSS) vulnerability in the CalendarInvite feature of the Zimbra webmail classic user interface. An attacker can exploit this vulnerability via an email message containing a crafted calendar header, leading to the execution of arbitrary JavaScript code.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
May 19, 2025 (federal fix deadline Jun 9, 2025)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog wiki.zimbra.com wiki.zimbra.com
Feb 25, 2025Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) VulnerabilityCVE-2023-34192 · Email & office · Synacor · reported by MITREExploitedCritical 9
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting (XSS) vulnerability that allows a remote authenticated attacker to execute arbitrary code via a crafted script to the /h/autoSaveDraft function.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Feb 25, 2025 (federal fix deadline Mar 18, 2025)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog wiki.zimbra.com wiki.zimbra.com
Oct 3, 2024Synacor Zimbra Collaboration Suite (ZCS) Command Execution VulnerabilityCVE-2024-45519 · Email & office · Synacor · reported by MITREExploitedCritical 10
Synacor Zimbra Collaboration Suite (ZCS) contains an unspecified vulnerability in the postjournal service that may allow an unauthenticated user to execute commands.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Oct 3, 2024 (federal fix deadline Oct 24, 2024)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog wiki.zimbra.com wiki.zimbra.com
Jul 27, 2023Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) VulnerabilityCVE-2023-37580 · Email & office · Synacor · reported by MITREExploitedMedium 6.1
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability impacting the confidentiality and integrity of data.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Jul 27, 2023 (federal fix deadline Aug 17, 2023)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog openwall.com wiki.zimbra.com
Apr 3, 2023Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) VulnerabilityCVE-2022-27926 · Email & office · Synacor · reported by MITREExploitedMedium 6.1
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability by allowing an endpoint URL to accept parameters without sanitizing.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Apr 3, 2023 (federal fix deadline Apr 24, 2023)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog wiki.zimbra.com wiki.zimbra.com
Oct 20, 2022Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload VulnerabilityCVE-2022-41352 · Email & office · Synacor · reported by MITREExploitedRansomwareCritical 9.8
Synacor Zimbra Collaboration Suite (ZCS) allows an attacker to upload arbitrary files using cpio package to gain incorrect access to any other user accounts.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Oct 20, 2022 (federal fix deadline Nov 10, 2022)
What to do
Attackers are using this now. Install Synacor’s update today (ransomware groups use this one). If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog packetstormsecurity.com forums.zimbra.org
Aug 11, 2022Synacor Zimbra Collaboration Suite (ZCS) Authentication Bypass VulnerabilityCVE-2022-37042 · Email & office · Synacor · reported by MITREExploitedRansomwareCritical 9.8
Synacor Zimbra Collaboration Suite (ZCS) contains an authentication bypass vulnerability in MailboxImportServlet. This vulnerability was chained with CVE-2022-27925 which allows for unauthenticated remote code execution.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Aug 11, 2022 (federal fix deadline Sep 1, 2022)
What to do
Attackers are using this now. Install Synacor’s update today (ransomware groups use this one). If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog packetstormsecurity.com wiki.zimbra.com
Aug 11, 2022Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload VulnerabilityCVE-2022-27925 · Email & office · Synacor · reported by MITREExploitedRansomwareHigh 7.2
Synacor Zimbra Collaboration Suite (ZCS) contains flaw in the mboximport functionality, allowing an authenticated attacker to upload arbitrary files to perform remote code execution. This vulnerability was chained with CVE-2022-37042 which allows for unauthenticated remote code execution.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Aug 11, 2022 (federal fix deadline Sep 1, 2022)
What to do
Attackers are using this now. Install Synacor’s update today (ransomware groups use this one). If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog packetstormsecurity.com wiki.zimbra.com
Aug 4, 2022Synacor Zimbra Collaboration Suite (ZCS) Command Injection VulnerabilityCVE-2022-27924 · Email & office · Synacor · reported by MITREExploitedRansomwareHigh 7.5
Synacor Zimbra Collaboration Suite (ZCS) allows an attacker to inject memcache commands into a targeted instance which causes an overwrite of arbitrary cached entries.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Aug 4, 2022 (federal fix deadline Aug 25, 2022)
What to do
Attackers are using this now. Install Synacor’s update today (ransomware groups use this one). If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog wiki.zimbra.com wiki.zimbra.com
Apr 19, 2022Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) VulnerabilityCVE-2018-6882 · Email & office · Synacor · reported by MITREExploitedRansomwareMedium 6.1
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability that might allow remote attackers to inject arbitrary web script or HTML.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Apr 19, 2022 (federal fix deadline May 10, 2022)
What to do
Attackers are using this now. Install Synacor’s update today (ransomware groups use this one). If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog seclists.org securityfocus.com
Jan 10, 2022Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External Entity ReferenceCVE-2019-9670 · Email & office · Synacor · reported by MITREExploitedCritical 9.8
Synacor Zimbra Collaboration Suite (ZCS) contains an improper restriction of XML external entity (XXE) vulnerability in the mailboxd component.
Product
Zimbra Collaboration Suite (ZCS)
On CISA’s list since
Jan 10, 2022 (federal fix deadline Jul 10, 2022)
What to do
Attackers are using this now. Install Synacor’s update today. If there is no update for your version, take the product off the internet or stop using it until there is.
Full record and what to do →NVD record CISA catalog packetstormsecurity.com rapid7.com

Where this comes from: the exploited list is CISA’s Known Exploited Vulnerabilities catalog. Everything else is the whole National Vulnerability Database, where each record is published by the team that found the bug (Wordfence, Patchstack, WPScan, the vendors themselves and others); we show who. Exploit odds are FIRST’s EPSS, updated daily. Titles and categories are ours, so check the linked record before acting on a detail. For a write-up of the big ones, see our advisories. Every vendor, and every WordPress plugin and theme with a recorded flaw, also has its own page. All of it is free to reuse as JSON, CSV or RSS.

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Vulnerability database

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