cvedb.io
CVE-2026-33128
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2026-03-20T10:16:19.160 · Last modified 2026-06-17T10:36:59.670

Summary

H3 is a minimal H(TTP) framework. In versions prior to 1.15.6 and between 2.0.0 through 2.0.1-rc.14, createEventStream is vulnerable to Server-Sent Events (SSE) injection due to missing newline sanitization in formatEventStreamMessage() and formatEventStreamComment(). An attacker who controls any part of an SSE message field (id, event, data, or comment) can inject arbitrary SSE events to connected clients. This issue is fixed in versions 1.15.6 and 2.0.1-rc.15.

Affected products

h3 — h3

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.