CVE-2026-55248
plone.app.portlets: Denial of service via RSS feed portlet
- State
- Published
- Severity
- 9.1 Critical
- Published
- Aug 28, 2026
- Updated
- Aug 28, 2026
- Reserved
- Jun 16, 2026
Description
plone.app.portlets provides portlets and a Plone-specific user interface for plone.portlets. Prior to 5.0.8, 6.0.4, and 7.0.2, a member who can add an RSS portlet can set its feed URL to a very large response, causing src/plone/app/portlets/portlets/rss.py to download and retain excessive data in memory and deny service. The same RSS URL handling accepts internal hosts, IP addresses, single-word domains, and explicit ports, allowing server-side requests that can probe internal network services and open ports. A malicious feed item can also supply a JavaScript URL that is retained as the item link and can execute script when used by a victim. The affected logic includes _rss_feed_url_validator, _normal_url_validator, RSSFeed._retrieveFeed, RSSFeed._buildItemDict, and the FEED_DATA in-memory cache. This issue is fixed in versions 5.0.8, 6.0.4, and 7.0.2.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.1 Critical | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H | GitHub_M |
Weaknesses
- CWE-400 Uncontrolled Resource Consumption
Affected Products
| Product | Versions |
|---|---|
plone.app.portletsplone |
|
References
- https://github.com/plone/plone.app.portlets/security/advisories/GHSA-x5g3-w747-2h8q
- https://github.com/plone/plone.app.portlets/commit/09da52ef7b297daa8e0cfd2361e47c37d9b073ad
- https://github.com/plone/plone.app.portlets/commit/9f16b6fb10211916686c6c346ea174bf517e3fbd
- https://github.com/plone/plone.app.portlets/commit/a3b2c2887165b308cd915cbb87b8276f90a76680
- https://github.com/plone/plone.app.portlets/commit/df5e256baee55083cbd6b9a2623675d4cb26b6cd
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