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CVE-2026-61909 (GCVE-0-2026-61909)

Vulnerability from cvelistv5 – Published: 2026-09-09 00:00 – Updated: 2026-09-09 19:50
VLAI
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 contacts by including the target hrefs in a calendar-multiget or addressbook-multiget REPORT.
Severity
3.5 (Low)
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N
CWE
  • CWE-420 - Unprotected Alternate Channel
Assigner
References
Impacted products
Vendor Product Version CPE status
cyrusimap Cyrus IMAP Affected: 0 , < 3.8.8 (semver)
Affected: 3.9.0 , < 3.10.4 (semver)
Affected: 3.11.0 , < 3.12.4 (semver)
    cpe:2.3:a:cyrusimap:cyrus_imap:*:*:*:*:*:*:*:*
    cpe:2.3:a:cyrusimap:cyrus_imap:*:*:*:*:*:*:*:*
    cpe:2.3:a:cyrusimap:cyrus_imap:*:*:*:*:*:*:*:*
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{
  "containers": {
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          "product": "Cyrus IMAP",
          "vendor": "cyrusimap",
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              "version": "3.9.0",
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            }
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      ],
      "cpeApplicability": [
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                },
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              "negate": false,
              "operator": "OR"
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        }
      ],
      "metrics": [
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            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 3.5,
            "baseSeverity": "LOW",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
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            "version": "3.1"
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      "problemTypes": [
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              "description": "CWE-420 Unprotected Alternate Channel",
              "lang": "en",
              "type": "CWE"
            }
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      "providerMetadata": {
        "dateUpdated": "2026-09-09T19:50:09.056Z",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
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      "references": [
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          "url": "https://cyrusimap.org"
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        },
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        },
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  "cveMetadata": {
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    "assignerShortName": "mitre",
    "cveId": "CVE-2026-61909",
    "datePublished": "2026-09-09T00:00:00.000Z",
    "dateReserved": "2026-07-13T00:00:00.000Z",
    "dateUpdated": "2026-09-09T19:50:09.056Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
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      "date": "2026-09-13",
      "epss": "0.00204",
      "percentile": "0.1052"
    },
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-10T07:59:45+00:00",
      "cve": "CVE-2026-61909",
      "id": "CVE-2026-61909",
      "initial_release_date": "2026-09-10T07:42:41.806000+00:00",
      "product_status:known_affected": "20",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "cyrus-imapd: cyrus-imapd: CalDAV/CardDAV multiget bypasses per-href ACL",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-61909.json",
      "version": "3"
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      "current_release_date": "2026-09-10T16:50:43Z",
      "cve": "CVE-2026-61909",
      "id": "CVE-2026-61909",
      "initial_release_date": "2026-09-10T16:50:43Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-61909",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-61909.json",
      "version": "2"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.