Eclipse Vert.x up to 5.0.12/5.1.9/5.2.0 HTTP/1.x decoder request smuggling

Summaryinfo

A vulnerability was found in Eclipse Vert.x up to 5.0.12/5.1.9/5.2.0. It has been declared as problematic. This issue affects some unknown processing of the component HTTP1.x decoder. Such manipulation leads to request smuggling. This vulnerability is traded as CVE-2026-102479. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Eclipse Vert.x up to 5.0.12/5.1.9/5.2.0 and classified as problematic. Affected by this issue is some unknown processing of the component HTTP1.x decoder. The manipulation with an unknown input leads to a request smuggling vulnerability. Using CWE to declare the problem leads to CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. Impacted is integrity. CVE summarizes:

In Eclipse Vert.x versions [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], the Vert.x HTTP/1.x decoder uses a canonicalization for well known HTTP headers, the canonicalization process interprets well crafted headers as headers of this list, allowing for instance Content-Xength to be interpeted as Content-Length. This can be exploited for request smuggling purpose. The impacted component is io.vertx:vertx-core.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-102479 since 09/29/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/14/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• Eclipse

Name

• Vert.x

Version

• 5.0
• 5.0.0
• 5.0.1
• 5.0.2
• 5.0.3
• 5.0.4
• 5.0.5
• 5.0.6
• 5.0.7
• 5.0.8
• 5.0.9
• 5.0.10
• 5.0.11
• 5.0.12
• 5.1
• 5.1.0
• 5.1.1
• 5.1.2
• 5.1.3
• 5.1.4
• 5.1.5
• 5.1.6
• 5.1.7
• 5.1.8
• 5.1.9
• 5.2.0

License

• open-source

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CPE 2.2info

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