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TI-2026-39921 Aliases CVE-2026-55248GHSA-x5g3-w747-2h8q

plone.app.portlets: Denial of service via RSS feed portlet

Priority MEDIUM 40CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
Low · Low · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-400.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00441 38th percentileScored 2026-11-08
Fix Fixed plone.app.portlets (plone): 5.0.8, 6.0.4, 7.0.2plone.app.portlets (PyPI): 7.0.2, 6.0.4, 5.0.8

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ploneplone.app.portletsbefore 5.0.8; 6.0.0 to before 6.0.4; 7.0.0 to before 7.0.25.0.8, 6.0.4, 7.0.2Patch availableCNA
—plone.app.portlets (PyPI)7.0.0 to before 7.0.27.0.2Patch availableGHSA-x5g3-w747-2h8q
—plone.app.portlets (PyPI)6.0.0 to before 6.0.46.0.4Patch availableGHSA-x5g3-w747-2h8q
—plone.app.portlets (PyPI)before 5.0.85.0.8Patch availableGHSA-x5g3-w747-2h8q
  • plone.app.portlets Vendorplone Affected before 5.0.8; 6.0.0 to before 6.0.4; 7.0.0 to before 7.0.2 Fixed in 5.0.8, 6.0.4, 7.0.2 Patch available CNA
  • plone.app.portlets (PyPI) Vendor— Affected 7.0.0 to before 7.0.2 Fixed in 7.0.2 Patch available GHSA-x5g3-w747-2h8q
  • plone.app.portlets (PyPI) Vendor— Affected 6.0.0 to before 6.0.4 Fixed in 6.0.4 Patch available GHSA-x5g3-w747-2h8q
  • plone.app.portlets (PyPI) Vendor— Affected before 5.0.8 Fixed in 5.0.8 Patch available GHSA-x5g3-w747-2h8q

Remediation

  • Fix · CNA plone.app.portlets (plone) Fixed in 5.0.8, 6.0.4, 7.0.2
  • Fix · GHSA-x5g3-w747-2h8q plone.app.portlets (PyPI) Fixed in 7.0.2 Advisory →
  • Fix · GHSA-x5g3-w747-2h8q plone.app.portlets (PyPI) Fixed in 6.0.4 Advisory →
  • Fix · GHSA-x5g3-w747-2h8q plone.app.portlets (PyPI) Fixed in 5.0.8 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-55248
  2. 2026-10-03 Alias added: GHSA-x5g3-w747-2h8q

References

Other 6

  • TI-2024-15205 An issue in Plone Docker Official Image 5.2.13 (5221) open-source software that could… CVSS 3.1CRITICAL 9.8
  • TI-2011-03162 Unspecified vulnerability in Zope 2.12.x and 2.13.x, as used in Plone 4.0.x through… CVSS 2.0HIGH 9.3
  • TI-2021-13226 An issue in Plone CMS v. CVSS 3.1HIGH 8.8
  • TI-2024-15757 The HTTP PUT and DELETE methods are enabled in the Plone official Docker version 5.2.13… CVSS 3.1HIGH 7.5
  • TI-2024-15206 An issue in Plone Docker Official Image 5.2.13 (5221) open-source software allows for… CVSS 3.1MEDIUM 6.1
  • TI-2008-01340 Plone CMS 3.0.5, and probably other 3.x versions, places a base64 encoded form of the… CVSS 2.0HIGH 10.0
See all 122 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences