In versions up to and including 4.5.29 (4.x branch) and 5.1.4 (5.x branch), the WebClientSession component of Eclipse Vert.x Web Client does not validate that the Domain attribute of a Set-Cookie response header matches the originating server's domain, in violation of RFC 6265 section 5.3.
An attacker who controls any server that the victim application contacts can inject a cookie scoped to an arbitrary third-party domain; because the session store performs no cross-domain ownership check, it stores and later transmits that cookie to the targeted domain.
When the victim application subsequently sends a request to the targeted domain using the same WebClientSession, it presents the attacker-injected cookie, causing the receiving service to process the request under the attacker's account. Sensitive data included in the victim application's requests, such as payment amounts, card details, or other API payloads, may then be accessible to the attacker through their own account on that service.
An attacker who controls any server that the victim application contacts can inject a cookie scoped to an arbitrary third-party domain; because the session store performs no cross-domain ownership check, it stores and later transmits that cookie to the targeted domain.
When the victim application subsequently sends a request to the targeted domain using the same WebClientSession, it presents the attacker-injected cookie, causing the receiving service to process the request under the attacker's account. Sensitive data included in the victim application's requests, such as payment amounts, card details, or other API payloads, may then be accessible to the attacker through their own account on that service.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 14 Jul 2026 13:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Tue, 14 Jul 2026 10:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Eclipse
Eclipse vert.x |
|
| Vendors & Products |
Eclipse
Eclipse vert.x |
Tue, 14 Jul 2026 08:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In versions up to and including 4.5.29 (4.x branch) and 5.1.4 (5.x branch), the WebClientSession component of Eclipse Vert.x Web Client does not validate that the Domain attribute of a Set-Cookie response header matches the originating server's domain, in violation of RFC 6265 section 5.3. An attacker who controls any server that the victim application contacts can inject a cookie scoped to an arbitrary third-party domain; because the session store performs no cross-domain ownership check, it stores and later transmits that cookie to the targeted domain. When the victim application subsequently sends a request to the targeted domain using the same WebClientSession, it presents the attacker-injected cookie, causing the receiving service to process the request under the attacker's account. Sensitive data included in the victim application's requests, such as payment amounts, card details, or other API payloads, may then be accessible to the attacker through their own account on that service. | |
| Weaknesses | CWE-346 | |
| References |
| |
| Metrics |
cvssV4_0
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: eclipse
Published:
Updated: 2026-07-14T12:20:29.616Z
Reserved: 2026-07-08T15:26:03.652Z
Link: CVE-2026-15076
Updated: 2026-07-14T12:20:24.619Z
No data.
No data.
OpenCVE Enrichment
Updated: 2026-07-14T10:00:07Z
Weaknesses