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CVE-2026-73575 Zimbra CVE debrief

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-08-13T16:19:06.767Z and has not been modified since then. The NVD entry is currently Awaiting Analysis. The CVE-2026-73575 vulnerability exists in the Exchange Web Services (EWS) endpoint of Zimbra Collaboration (ZCS) before version 10.1.17. The vulnerability is caused by insufficient validation of request content types, allowing an attacker to perform Cross-Site Request Forgery (CSRF) attacks. An attacker can exploit this vulnerability by causing an authenticated user to submit a crafted request, potentially allowing unauthorized actions to be performed on behalf of the victim. Organizations using Zimbra Collaboration (ZCS) versions prior to 10.1.17 should be aware of this CSRF vulnerability in the Exchange Web Services (EWS) endpoint and take steps to mitigate the risk. The debrief provides an executive overview covering the affected product, vulnerability class, likely operational impact, and source-confidence limits.

Vendor
Zimbra
Product
Collaboration
CVSS
LOW 3.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-13
Original CVE updated
2026-08-21
Advisory published
2026-08-13
Advisory updated
2026-08-21

Who should care

Organizations using Zimbra Collaboration (ZCS) versions prior to 10.1.17 should be aware of this CSRF vulnerability in the Exchange Web Services (EWS) endpoint and take steps to mitigate the risk.

Technical summary

The CVE-2026-73575 vulnerability exists in the Exchange Web Services (EWS) endpoint of Zimbra Collaboration (ZCS) before version 10.1.17. The vulnerability is caused by insufficient validation of request content types, allowing an attacker to perform Cross-Site Request Forgery (CSRF) attacks. An attacker can exploit this vulnerability by causing an authenticated user to submit a crafted request, potentially allowing unauthorized actions to be performed on behalf of the victim.

Defensive priority

Organizations using Zimbra Collaboration (ZCS) should prioritize patching to prevent potential unauthorized actions.

Recommended defensive actions

  • Apply patches or updates to Zimbra Collaboration (ZCS) to version 10.1.17 or later
  • Implement additional security measures to monitor and restrict EWS endpoint requests
  • Educate users about the risks of CSRF attacks and the importance of verifying request authenticity
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE-2026-73575 record indicates a Cross-Site Request Forgery (CSRF) vulnerability in Zimbra Collaboration (ZCS) before 10.1.17, specifically in the Exchange Web Services (EWS) endpoint, due to insufficient validation of request content types. An attacker could exploit this by causing an authenticated user to submit a crafted request, potentially allowing unauthorized actions on behalf of the victim. However, detailed information about affected configurations and vendor remediation is limited in the provided source corpus.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-08-13T16:19:06.767Z and has not been modified since then.