CVE-2026-55247

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Source

https://cve.org/CVERecord?id=CVE-2026-55247

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55247.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-55247

Aliases

Published

2026-08-28T18:59:01Z

Modified

2026-10-28T02:31:01Z

Severity

9.1 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H CVSS Calculator

Summary

plone.app.event: Denial of service via iCalendar import

Details

plone.app.event provides the event content type for Plone. Prior to versions 5.2.4 and 6.0.1, the iCalendar import in src/plone/app/event/ical/importer.py accepts insufficiently restricted calendar and event URLs, does not adequately bound downloaded bytes or imported events, and commits work per event. A logged-in editor can make the server request internal network resources or local calendar files, exhaust resources and take the site offline, and store a malicious event URL that executes script in another user's browser. The fix restricts accepted URLs, applies MAXIMUM_ICAL_IMPORT_SIZE_BYTES and MAXIMUM_ICAL_IMPORT_EVENTS limits, uses transaction savepoints, and validates event URLs. This issue is fixed in versions 5.2.4 and 6.0.1.

Database specific

{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-400"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55247.json"
}

References

Affected packages

Git / github.com/plone/plone.app.event

Affected ranges

Type

GIT

Repo

https://github.com/plone/plone.app.event

Events

Introduced

Fixed

67343d3385073c618d37f3835e7575e010fa1ca7

Introduced

f77cb42d990b2dcdf0d0c5e9baceb9977713565a

Fixed

0bbaa2f5d32625d5cb895089c7d974c775b36ce6

Fixed

1e3c83c15a24d1a789cdb012593505bc5620e28e

Fixed

4de5eb3ea9e4f7f1781622e6d64fc086629d1437

Database specific

Show details

{
    "extracted_events": [
        {
            "range": [
                {
                    "introduced": "0"
                },
                {
                    "fixed": "5.2.4"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StringRangeExpression"
        },
        {
            "range": [
                {
                    "introduced": "6.0.0"
                },
                {
                    "fixed": "6.0.1"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StringRangeExpression"
        },
        {
            "range": [
                {
                    "fixed": "1e3c83c15a24d1a789cdb012593505bc5620e28e"
                }
            ],
            "source": "REFERENCES_COMMIT"
        },
        {
            "range": [
                {
                    "fixed": "4de5eb3ea9e4f7f1781622e6d64fc086629d1437"
                }
            ],
            "source": "REFERENCES_COMMIT"
        },
        {
            "original_tag": "5.2.4",
            "range": [
                {
                    "fixed": "67343d3385073c618d37f3835e7575e010fa1ca7"
                }
            ],
            "source": "REFERENCES_TAG"
        },
        {
            "original_tag": "6.0.1",
            "range": [
                {
                    "fixed": "0bbaa2f5d32625d5cb895089c7d974c775b36ce6"
                }
            ],
            "source": "REFERENCES_TAG"
        }
    ]
}

Affected versions

1.*

1.0a1

1.0b1

1.0b2

1.0b3

1.0b4

1.0b5

1.0b6

1.0b8

1.0htug1

1.0htug10

1.0htug11

1.0htug13

1.0htug15

1.0htug16

1.0htug2

1.0htug3

1.0htug8

1.0htug9

1.0rc1

1.0rc2

1.0rc3

1.1.a1

2.*

2.0.1

2.0.2

2.0.3

2.0.4

2.0.5

2.0.6

2.0.7

2.0.8

2.0.9

2.0a1

2.0a10

2.0a12

2.0a13

2.0a2

2.0a3

2.0a4

2.0a5

2.0a6

2.0a7

2.0a8

2.0a9

2.0b1

2.0b2

3.*

3.0

3.0.1

3.0.2

3.0.3

3.0.4

3.0.5

3.0.6

3.0.7

3.1

3.1.1

3.2.0

3.2.1

3.2.10

3.2.2

3.2.3

3.2.4

3.2.5

3.2.6

3.2.7

3.2.8

3.2.9

4.*

4.0.0

4.0.0a1

4.0.0a2

4.0.0a3

4.0.0a4

4.0.0a5

4.0.0a6

4.0.0a7

4.0.0a8

4.0.0a9

4.0.0b1

5.*

5.0.0

5.0.1

5.1.0

5.1.1

5.1.2

5.1.3

5.1.4

5.1.5

5.1.6

5.1.7

5.1.8

5.2.0

5.2.1

5.2.2

5.2.3

6.*

6.0.0

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55247.json"