---
id: CVE-2026-61909
title: An issue was discovered in Cyrus IMAP before 3.12.4
summary: >-
  An issue was discovered in Cyrus IMAP before 3.12.4. CalDAV/CardDAV multiget
  bypasses a per-href ACL. An authenticated DAV user with some shared access to
  another user's calendar or address book could read even unshared events or
  contact…
severity: low
cvss: 3.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N'
cwe:
  - CWE-420
vendor: cyrus
product: imap
affected:
  - imap < 3.8.8
  - 'imap >= 3.9.0, < 3.10.4'
  - 'imap >= 3.11.0, < 3.12.4'
patched:
  - imap 3.12.4
published: '2026-09-09'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T15:24:24.070'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-61909'
references:
  - url: 'https://cyrusimap.org'
    label: cve@mitre.org
  - url: >-
      https://www.cyrusimap.org/3.12/imap/download/release-notes/3.10/x/3.10.4.html
    label: cve@mitre.org
  - url: >-
      https://www.cyrusimap.org/3.12/imap/download/release-notes/3.12/x/3.12.4.html
    label: cve@mitre.org
  - url: >-
      https://www.cyrusimap.org/3.12/imap/download/release-notes/3.8/x/3.8.8.html
    label: cve@mitre.org
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-61909.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-61909'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2526308'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-61909'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-61909'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.0035
epssPercentile: 0.25987
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-14T15:17:37.307793Z'
ingestedAt: '2026-09-14T02:42:26.849Z'
scores:
  nvd: 3.5
  vendor: 5
---

## Overview

An issue was discovered in Cyrus IMAP before 3.12.4. CalDAV/CardDAV multiget bypasses a per-href ACL. An authenticated DAV user with some shared access to another user's calendar or address book could read even unshared events or contacts by including the target hrefs in a calendar-multiget or addressbook-multiget REPORT.

## Affected

- `imap < 3.8.8`
- `imap >= 3.9.0, < 3.10.4`
- `imap >= 3.11.0, < 3.12.4`

## Remediation

Upgrade past the affected range:

- `imap 3.12.4`

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-61909.json)