In Eclipse Vert.x versions up to and including 4.5.29 (4.x branch) and 5.1.4 (5.x branch), DefaultRedirectHandler (vertx-core) propagates all request headers as-is across cross-origin HTTP 30x redirects. Only Content-Length is stripped; no origin comparison (scheme, host, port) is performed before copying headers to the redirect target. As a result, credential headers, including Authorization, Cookie, Proxy-Authorization, and arbitrary custom headers such as X-API-Token, are forwarded to the redirect destination without the caller's knowledge. An attacker who can cause a Vert.x HttpClient to issue a request that is redirected to an attacker-controlled host (for example, by supplying a URL to a webhook dispatcher, image proxy, or microservice URL fetcher) can capture bearer tokens, basic-auth credentials, session cookies, and API keys attached to the original request.
https://gitlab.eclipse.org/security/cve-assignment/-/work_items/161
Published: 2026-07-14
Updated: 2026-07-14
Base Score: 5.8
Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:N
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
Base Score: 8.2
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00154