Description

RSS/Atom feed handlers bypass API-token scope & public-only confinement (incomplete fix of #37698)

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.3",
  "pubDate": "2026-08-13T17:17:23.387Z",
  "pubdate": "2026-08-13T17:17:23.387Z",
  "executiveSummary": "This vulnerability involves an incomplete fix for issue #37698, specifically residing within the RSS and Atom feed handlers. The flaw allows malicious actors to bypass established API-token scope restrictions and public-only data confinement boundaries. Consequently, unauthorized entities can access sensitive feeds and data streams that should otherwise be strictly protected by token limitations or confinement policies. The risk implications include unauthorized information disclosure, data exfiltration, and potential compromise of confidential system or user metrics exposed through feed endpoints. Attackers require a valid interaction mechanism targeting the vulnerable feed handlers to trigger the bypass. Exploitation prerequisites primarily hinge upon the inadequate validation logic within the affected RSS/Atom parsing and handling routines, which fail to properly enforce scope constraints during request processing. Because the system relies on flawed access control checks within these specific handlers, malicious requests circumvent API token limitations without requiring advanced administrative privileges, directly undermining the security posture of the affected application.",
  "technicalDetails": "The root cause of this vulnerability stems from an incomplete remediation of issue #37698, where validation mechanisms for API-token scopes and public-only confinement were improperly implemented within the RSS/Atom feed handlers. The vulnerable components are the feed parsing and request handling modules responsible for processing incoming syndication requests. Network exposure is present wherever the RSS or Atom endpoints are accessible to clients submitting API tokens. Authentication and privilege requirements are bypassed due to the flawed logic; an attacker presenting a restricted API token or attempting to access non-public feeds can successfully coerce the handler into serving restricted content. The exploitation method relies on sending crafted requests to the RSS or Atom feed handlers that manipulate or omit scope validation checks. The attack flow proceeds as follows: First, the attacker identifies the feed endpoints exposed by the application. Second, the attacker issues a request to the RSS/Atom handler utilizing an API token with limited privileges or targeting resources restricted to public-only access. Third, because the underlying authorization checks fail to adequately verify token scopes or confinement rules due to the incomplete fix, the handler processes the request as if it originated from a fully authorized or unrestricted context. Finally, the server responds by disclosing sensitive feed data that violates the intended security policy. Payload behavior involves leveraging standard syndication protocol parameters to elicit unauthorized data responses. The post-exploitation impact is characterized by unauthorized data access and information disclosure, enabling adversaries to harvest confidential feed contents, internal state data, or restricted metadata that bypasses the intended confinement boundary."
}