How severe is CVE-2026-73571?

CVE-2026-73571 has a CVSS 3.x base score of 3.1, rated low severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-73571 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-73571?

CVE-2026-73571 affects Synacor Zimbra Collaboration Suite. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-73571?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-73571 published?

CVE-2026-73571 was published on 2026-08-13 and last updated on 2026-08-28.

CVE-2026-73571

CVE-2026-73571 is a low-severity vulnerability in Synacor Zimbra Collaboration Suite with a CVSS 3.x base score of 3.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Low (CVSS 3.x base score 3.1)
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Synacor Zimbra Collaboration Suite
Published: 2026-08-13
Last modified: 2026-08-28

Description

An authorization bypass vulnerability exists in Zimbra Collaboration (ZCS) before 10.1.17 due to improper authorization validation in delegated email sending functionality. An authenticated attacker can send specially crafted SOAP requests to impersonate another user and send emails without possessing the required delegation or send-as permissions. This occurs in the SaveDraftRequest SOAP handler.

Frequently asked questions

What is CVE-2026-73571?: An authorization bypass vulnerability exists in Zimbra Collaboration (ZCS) before 10.1.17 due to improper authorization validation in delegated email sending functionality. An authenticated attacker can send specially crafted SOAP requests to impersonate another user and send emails without possessing the required delegation or send-as permissions. This occurs in the SaveDraftRequest SOAP handler.
How severe is CVE-2026-73571?: CVE-2026-73571 has a CVSS 3.x base score of 3.1, rated low severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-73571 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-73571?: CVE-2026-73571 affects Synacor Zimbra Collaboration Suite. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-73571?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-73571 published?: CVE-2026-73571 was published on 2026-08-13 and last updated on 2026-08-28.

References

Affected products (1)

cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*

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