Bug 2501449 (CVE-2026-47082)

Summary:	CVE-2026-47082 cyrus-imapd: Cyrus IMAP: ACL bypass in vacation 'fcc' feature allows unauthorized mailbox writes
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in Cyrus IMAP's cyrus-imapd component. A user with low privileges can exploit a vulnerability in the vacation "fcc" feature. By crafting a specific Sieve script, the user can bypass access control lists and deliver vacation auto-reply messages into any mailbox, leading to unauthorized modification of mailbox content.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2501668
Bug Blocks:

Description OSIDB Bzimport 2026-07-16 19:01:31 UTC

An issue was discovered in cyrus-imapd in Cyrus IMAP through 3.12.2. The vacation "fcc" feature skips the destination-mailbox ACL. A user whose vacation Sieve script used :fcc (to save a copy of the sent message) could deliver vacation auto-reply copies into any mailbox the script could name, regardless of whether the script owner had insert permissions on the destination mailbox.