Apprise, an open‑source notification library, forwards user‑configured authentication headers, bearer tokens, custom headers, and query parameters when it follows HTTP redirects. The default behavior in HTTP‑based notification plugins and loader modules causes the same headers to be resent to the redirected target, exposing sensitive data that was intended for a trusted endpoint. This constitutes an information disclosure vulnerability, aligned with CWE‑200, CWE‑201, and the cross‑site redirect weakness CWE‑601.

Apprise provided by caronc is vulnerable in all releases prior to version 1.11.0. The fix appears in release 1.11.0 and later; any earlier version remains at risk.

The CVSS score of 3.1 indicates low severity, and the EPSS score is less than 1 %, implying limited known exploitation activity. The vulnerability is not listed in the CISA KEV catalog. Likely exploitation requires an application or user to send an HTTP request to a malicious or compromised service that issues a redirect, enabling the attacker to capture the forwarded authentication headers. The risk is primarily accidental leakage of credentials, but exposure of highly sensitive tokens or service keys can have significant consequences.