Zimbra Collaboration Suite Sieve Notify Filter Action Bypasses Mail Forwarding Restriction via Variable Expansion

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-50055
StatePUBLISHED
Assignerrapid7
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-08 17:17:17 UTC
Updated2026-10-08 20:49:23 UTC
DescriptionA policy-enforcement flaw in Zimbra Collaboration Suite allows an authenticated user to bypass disabled mail forwarding by using a Sieve notify action to send copies of email content and headers to an arbitrary address.

Risk And Classification

Primary CVSS: v3.1 6.5 MEDIUM from [email protected]

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

Problem Types: CWE-863 | CWE-863 CWE-863 Incorrect Authorization

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary6.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
3.1CNACVSS6.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Zimbra Zimbra Collaboration Suite affected 10.1.20 semver Not specified

References

ReferenceSourceLinkTags
wiki.zimbra.com/wiki/Zimbra_Security_Advisories [email protected] wiki.zimbra.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Jonah Burgess (CryptoCat), Senior Security Researcher, Rapid7 (en)

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