CVE-2026-102479

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.

CVSS 4.0

8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.3% chance of exploitation in the next 30 days; higher than 18% of CVEs (scores of 2026-10-25)

CWE

CWE-444

Published

2026-10-14

Modified

2026-10-20

Record from

the NVD, synced 2026-10-21

Affected

• eclipse:vert.x

References

• https://github.com/eclipse-vertx/vert.x/security/advisories/GHSA-ch7p-g5pm-3gqx
• https://gitlab.eclipse.org/security/cve-assignment/-/work_items/352

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