Resource exhaustion in Plone Plone.app.portlets
CVE-2026-55248
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.
Vulnerability class: DoS (Denial of Service)
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H.
Affected products
- Plone Plone.app.portlets — versions < 5.0.8, >= 6.0.0, < 6.0.4, >= 7.0.0, < 7.0.2
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-55248?
- CVE-2026-55248 is a critical-severity vulnerability in Plone Plone.app.portlets, classified under Uncontrolled Resource Consumption. CVSS score: 9.1/10. Published 2026-08-28.
- How severe is CVE-2026-55248?
- Critical severity. CVSS v3 base score is 9.1 out of 10.