Security readout for executives and security teams
Plain-English summary
A Plone member permitted to add RSS portlets can make the server consume excessive memory, probe internal services, or expose visitors to script execution through a malicious feed link. Successful abuse could disrupt the site and create paths to internal-network discovery or user compromise.
Executive priority
Prioritize remediation for internet-facing Plone sites where non-administrative members can create RSS portlets. The combination of service disruption, internal-network probing, and possible script execution justifies urgent upgrading, although the supplied evidence does not show active exploitation.
Technical view
Affected plone.app.portlets RSS handling insufficiently restricts response size, destination URLs, and feed-item JavaScript URLs. FEED_DATA can retain oversized responses, causing memory exhaustion. Permissive URL validation enables server-side requests to internal hosts and ports, while unsafe item links can execute script. Fixed releases are 5.0.8, 6.0.4, and 7.0.2.
Likely exposure
Exposure requires an affected plone.app.portlets version and a member account authorized to add RSS portlets. Risk is higher where such members can choose arbitrary feed URLs, the server can reach sensitive internal services, or untrusted users view RSS portlet content.
Exploitation context
The supplied sources do not establish active exploitation, and the CVE is not identified as being in KEV. Exploitation nevertheless has low complexity and requires only low privileges according to CVSS 3.1, with no victim interaction required for the denial-of-service path.
Researcher notes
The affected ranges are below 5.0.8, 6.0.0 through 6.0.3, and 7.0.0 through 7.0.1. Relevant logic includes both URL validators, RSSFeed._retrieveFeed, RSSFeed._buildItemDict, and FEED_DATA caching. The CVE records CWE-400, while the description also documents server-side request and script-link impacts.
Mitigation direction
- Upgrade 5.x installations to 5.0.8 or later.
- Upgrade 6.x installations to 6.0.4 or later.
- Upgrade 7.x installations to 7.0.2 or later.
- Until upgraded, restrict permission to add or modify RSS portlets.
- Limit server outbound access to internal services where operationally feasible.
Validation and detection
- Inventory the installed plone.app.portlets version against the affected ranges.
- Confirm the deployed package reports the intended fixed version after upgrading.
- Identify accounts and roles permitted to add or modify RSS portlets.
- Review configured RSS URLs for internal hosts, explicit ports, or untrusted destinations.
- Verify outbound network controls prevent unnecessary access to sensitive internal services.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-55248 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H3.15.3GitHub_MVulnerability scoring details
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/plone/plone.app.portlets/security/advisories/GHSA-x5g3-w747-2h8qCVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/plone/plone.app.portlets/commit/09da52ef7b297daa8e0cfd2361e47c37d9b073adCVE reference, GitHub_M · x_refsource_MISC
- https://github.com/plone/plone.app.portlets/commit/9f16b6fb10211916686c6c346ea174bf517e3fbdCVE reference, GitHub_M · x_refsource_MISC
- https://github.com/plone/plone.app.portlets/commit/a3b2c2887165b308cd915cbb87b8276f90a76680CVE reference, GitHub_M · x_refsource_MISC
- https://github.com/plone/plone.app.portlets/commit/df5e256baee55083cbd6b9a2623675d4cb26b6cdCVE reference, GitHub_M · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.