Synacor vulnerabilities in CISA KEV
Synacor has 19 vulnerabilities in CISA's catalogue of flaws known to be exploited, the 15th highest of any vendor. 5 were added in the last 12 months; 6 are linked to known ransomware use (31.6% of its entries, against 20.4% across the catalogue). CISA's median fix window for these entries is 21 days (range 3 to 181), against 21 days (range 1 to 184) across the whole catalogue. The most exploited product is Zimbra Collaboration Suite (ZCS), with 16 entries. Other frequently affected products: Zimbra Collaboration Suite (ZCS) (1); Zimbra Collaborate Suite (ZCS) (1).
Catalog v2026.11.04, released 5 Nov 2026. Source CISA ↗. All KEV entries.
$ ./kev --vendor synacor --summary
Counts are computed from the catalog release on ; the 12 month window ends there.
┌─ total entries
19
in CISA KEV
┌─ first added
2022-01-10
earliest entry
┌─ latest added
2026-08-21
most recent entry
┌─ last 12 months
5
entries added
┌─ ransomware use
6 of 19
31.6% linked to ransomware
┌─ distinct products
4
affected products
$ awk -F, {print $1} /var/log/kev/synacor.log | uniq -c
Entries by the year CISA added them.
| Year | Entries added | Of which ransomware |
|---|---|---|
| 2022 | 7 | 6 |
| 2023 | 2 | 0 |
| 2024 | 1 | 0 |
| 2025 | 4 | 0 |
| 2026 | 5 | 0 |
$ sort /var/log/kev/synacor.log | uniq -c | sort -rn | head -5
The five products with the most entries in the catalogue.
- Zimbra Collaboration Suite (ZCS) 16 entries
- Zimbra Collaboration Suite (ZCS) 1 entry
- Zimbra Collaborate Suite (ZCS) 1 entry
- Zimbra Collaboration Suite 1 entry
$ kev-due-dates --vendor synacor
Days between the date CISA added an entry and the due date it set, median and range. Due dates apply to US federal agencies; for everyone else they are a patch-first ranking signal.
┌─ Synacor
21 days (range 3 to 181)
median and range in days
┌─ whole catalogue
21 days (range 1 to 184)
median and range in days
$ grep -o 'CWE-[0-9]*' /var/log/kev/synacor.log | sort | uniq -c | sort -rn | head -3
Weakness types CISA records for these entries (19 of 19 have at least one CWE).
$ grep -ril 'Synacor' /var/log/news | head -5
Our reporting that names Synacor or one of its KEV CVE ids, newest first.
┌─ /var/log/news
Patch Week pages with these entries
No Patch Week page covers this vendor yet.
$ wc -l ./synacor.kev · 19 rows
Descriptions: CISA Known Exploited Vulnerabilities catalogue
- CVE-2026-73570
Zimbra Collaboration Suite (ZCS)
Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability
due 2026-08-24 · CWE-78
$ cat CVE-2026-73570.txt
Description. 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.
Required action. Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
- CVE-2025-48700
Zimbra Collaboration Suite (ZCS)
Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability
due 2026-04-23 · CWE-79
$ cat CVE-2025-48700.txt
Description. 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.
Required action. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CVE-2025-66376
Zimbra Collaboration Suite (ZCS)
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability
due 2026-04-01 · CWE-79
$ cat CVE-2025-66376.txt
Description. 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.
Required action. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CVE-2020-7796
Zimbra Collaboration Suite
Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery Vulnerability
due 2026-03-10 · CWE-918
$ cat CVE-2020-7796.txt
Description. Synacor Zimbra Collaboration Suite (ZCS) contains a server-side request forgery vulnerability if WebEx zimlet installed and zimlet JSP is enabled.
Required action. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CVE-2025-68645
Zimbra Collaboration Suite (ZCS)
Synacor Zimbra Collaboration Suite (ZCS) PHP Remote File Inclusion Vulnerability
due 2026-02-12 · CWE-98
$ cat CVE-2025-68645.txt
Description. 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.
Required action. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CVE-2025-27915
Zimbra Collaboration Suite (ZCS)
Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability
due 2025-10-28 · CWE-79
$ cat CVE-2025-27915.txt
Description. 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.
Required action. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CVE-2019-9621
Zimbra Collaboration Suite (ZCS)
Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery (SSRF) Vulnerability
due 2025-07-28 · CWE-918 CWE-807
$ cat CVE-2019-9621.txt
Description. Synacor Zimbra Collaboration Suite (ZCS) contains a server-side request forgery (SSRF) vulnerability via the ProxyServlet component.
Required action. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CVE-2024-27443
Zimbra Collaboration Suite (ZCS)
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
due 2025-06-09 · CWE-79
$ cat CVE-2024-27443.txt
Description. 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.
Required action. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CVE-2023-34192
Zimbra Collaboration Suite (ZCS)
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
due 2025-03-18 · CWE-79
$ cat CVE-2023-34192.txt
Description. 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.
Required action. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CVE-2024-45519
Zimbra Collaboration Suite (ZCS)
Synacor Zimbra Collaboration Suite (ZCS) Command Execution Vulnerability
due 2024-10-24 · CWE-284
$ cat CVE-2024-45519.txt
Description. Synacor Zimbra Collaboration Suite (ZCS) contains an unspecified vulnerability in the postjournal service that may allow an unauthenticated user to execute commands.
Required action. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- CVE-2023-37580
Zimbra Collaboration Suite (ZCS)
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
due 2023-08-17 · CWE-79
$ cat CVE-2023-37580.txt
Description. Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability impacting the confidentiality and integrity of data.
Required action. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- CVE-2022-27926
Zimbra Collaboration Suite (ZCS)
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
due 2023-04-24 · CWE-79 CWE-138
$ cat CVE-2022-27926.txt
Description. Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability by allowing an endpoint URL to accept parameters without sanitizing.
Required action. Apply updates per vendor instructions.
- CVE-2022-41352
Zimbra Collaboration Suite (ZCS) [RANSOMWARE]
Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability
due 2022-11-10 · CWE-22
$ cat CVE-2022-41352.txt
Description. Synacor Zimbra Collaboration Suite (ZCS) allows an attacker to upload arbitrary files using cpio package to gain incorrect access to any other user accounts.
Required action. Apply updates per vendor instructions.
- CVE-2022-27925
Zimbra Collaboration Suite (ZCS) [RANSOMWARE]
Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability
due 2022-09-01 · CWE-22
$ cat CVE-2022-27925.txt
Description. 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.
Required action. Apply updates per vendor instructions.
- CVE-2022-37042
Zimbra Collaboration Suite (ZCS) [RANSOMWARE]
Synacor Zimbra Collaboration Suite (ZCS) Authentication Bypass Vulnerability
due 2022-09-01 · CWE-23
$ cat CVE-2022-37042.txt
Description. 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.
Required action. Apply updates per vendor instructions.
- CVE-2022-27924
Zimbra Collaboration Suite (ZCS) [RANSOMWARE]
Synacor Zimbra Collaboration Suite (ZCS) Command Injection Vulnerability
due 2022-08-25 · CWE-93
$ cat CVE-2022-27924.txt
Description. Synacor Zimbra Collaboration Suite (ZCS) allows an attacker to inject memcache commands into a targeted instance which causes an overwrite of arbitrary cached entries.
Required action. Apply updates per vendor instructions.
- CVE-2018-6882
Zimbra Collaboration Suite (ZCS) [RANSOMWARE]
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
due 2022-05-10 · CWE-79
$ cat CVE-2018-6882.txt
Description. Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability that might allow remote attackers to inject arbitrary web script or HTML.
Required action. Apply updates per vendor instructions.
- CVE-2022-24682
Zimbra Collaborate Suite (ZCS) [RANSOMWARE]
Synacor Zimbra Collaborate Suite (ZCS) Cross-Site Scripting Vulnerability
due 2022-03-11 · CWE-79 CWE-116
$ cat CVE-2022-24682.txt
Description. Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting (XSS) vulnerability in the Calendar feature that allows an attacker to execute arbitrary code.
Required action. Apply updates per vendor instructions.
- CVE-2019-9670
Zimbra Collaboration Suite (ZCS)
Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External Entity Reference
due 2022-07-10 · CWE-611
$ cat CVE-2019-9670.txt
Description. Synacor Zimbra Collaboration Suite (ZCS) contains an improper restriction of XML external entity (XXE) vulnerability in the mailboxd component.
Required action. Apply updates per vendor instructions.