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CVE Record

CVE-2026-2433: RSS Aggregator – RSS Import, News Feeds, Feed to Post, and Autoblogging <= 5.0.11 - Unauthenticated DOM-Based Reflected Cross-Site Scripting via postMessage

The RSS Aggregator – RSS Import, News Feeds, Feed to Post, and Autoblogging plugin for WordPress is vulnerable to DOM-Based Cross-Site Scripting via postMessage in all versions up to, and including, 5.0.11. This is due to the plugin's admin-shell.js registering a global message event listener without origin validation (missing event.origin check) and directly passing user-controlled URLs to window.open() without URL scheme validation. This makes it possible for unauthenticated attackers to execute arbitrary JavaScript in the context of an authenticated administrator's session by tricking them into visiting a malicious website that sends crafted postMessage payloads to the plugin's admin page.

MediumCVSS 6.1Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2026-2433 affects the WordPress RSS Aggregator plugin through version 5.0.11. An attacker could trick a logged-in administrator into visiting a malicious page, causing JavaScript to run in the admin’s browser in the site’s context. This is not described as actively exploited, but it can enable account-context actions or data exposure if an administrator is targeted.

Executive priority

Treat as a timely WordPress plugin remediation item, not an emergency based on current evidence. Prioritize sites where RSS Aggregator is installed, administrators are highly targeted, or the WordPress site supports business-critical publishing, commerce, or customer engagement.

Technical view

The plugin’s admin-shell.js registers a global postMessage listener without validating event.origin and passes user-controlled URLs to window.open() without URL scheme validation. The issue is DOM-based reflected XSS, unauthenticated, but requires user interaction by an authenticated administrator. CVSS 3.1 is 6.1, with low confidentiality and integrity impact and no availability impact.

Likely exposure

WordPress sites using RSS Aggregator – RSS Import, News Feeds, Feed to Post, and Autoblogging versions up to and including 5.0.11. Exposure is most relevant where administrators access plugin admin pages while also reachable through phishing or malicious websites.

Exploitation context

The published scenario requires tricking an authenticated administrator into visiting a malicious website that sends crafted postMessage data to the plugin’s admin page. The source bundle does not indicate CISA KEV listing or confirmed active exploitation.

Researcher notes

Evidence supports DOM XSS via missing postMessage origin validation and unsafe URL handling in admin-shell.js. The CVE states affected versions through 5.0.11. The provided sources include WordPress Trac code references and a changeset, but the bundle does not clearly name a fixed release version.

Mitigation direction

  • Inventory WordPress sites using the RSS Aggregator plugin.
  • Check installed plugin version and identify any instances at or below 5.0.11.
  • Update to a vendor-provided fixed version if available.
  • If no fix is available, follow WordPress plugin vendor guidance.
  • Warn administrators not to browse untrusted links while logged into WordPress.
  • Restrict administrator access to trusted networks where operationally feasible.

Validation and detection

  • Confirm whether the plugin is installed on each WordPress site.
  • Record the installed plugin version from WordPress administration or asset inventory.
  • Review vendor advisories for the first fixed version and remediation status.
  • Inspect plugin admin-shell.js for origin validation around postMessage handling.
  • Verify change management records show plugin update or compensating controls.
  • Monitor WordPress admin activity for unusual actions after administrator phishing exposure.
Prepared
Confidence
high
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · medium confidence lookup

CWE-79: User-session and phishing behavior lookup

Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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.

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cve · low confidence lookup

CVE-2026-2433 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.1 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
5Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
6.1CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N2.82.7Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.1Medium
CVSS 3.1 vector shape for CVE-2026-2433Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
rebelcodeRSS Aggregator – RSS Import, News Feeds, Feed to Post, and Autoblogging0unaffected
Weakness

CWE details

CWE-79

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.