CVE-2026-73571

LOW 3.1 ALL-YEARS

Published 2026-08-13 · Last modified 2026-08-13 · mitre · NVD: Analyzed

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.

LIMITED SIGNALS

No known exploitation, public exploit, or elevated probability at this time. Track for changes.

Exploitation likelihood

0.3%chance of exploitation in 30 days · 17th percentile

○ In CISA KEV○ Catalogued PoC◆ SSVC: exploitation none, automatable no

Impact if exploited

3.1CVSS 3.1 · LOW · CNA

ConfidentialityNone
IntegrityLow
AvailabilityNone

What an attacker needs

✓Access: Reachable over the network — no local access needed
⚠Privileges: Requires a low-privilege account
✓User interaction: No user interaction needed
⚠Complexity: Needs a race window or specific setup

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

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Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Affected

Vendors Zimbra Synacor

Products Collaboration Zimbra Collaboration Suite

Weakness (CWE)

CWE-863: Incorrect Authorization

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N

References and research data (JSON)

Known Affected Software Configurations

Vendor	Product	Version range
Synacor	Zimbra Collaboration Suite	< 10.1.17

All CVSS metrics

LOW 3.1 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
LOW 3.1 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
MEDIUM 4.3 v3.1 · NVD Primary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

References

Advisories

https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories Vendor AdvisoryCVE record · mitre · Updated 2026-08-13T15:36:39.678Z
NVD · CVE-2026-73571 · Updated 2026-08-28T13:58:23.877
https://wiki.zimbra.com/wiki/Security_Center Vendor AdvisoryCVE record · mitre · Updated 2026-08-13T15:36:39.678Z
NVD · CVE-2026-73571 · Updated 2026-08-28T13:58:23.877
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-58070 ADVISORYEUVD · EUVD-2026-58070

Sources: NVD · CVE.org · All sources and attribution · EPSS