Description
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.
CVSS Metrics
- Vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N
- Attack Vector
- network
- Complexity
- high
- Privileges
- none
- User Action
- none
- Scope
- changed
- Confidentiality
- low
- Integrity
- high
- Availability
- none
- Weaknesses
- CWE-93
Metadata
- Primary Vendor
- H3
- Published
- 3/20/2026
- Last Modified
- 3/20/2026
- Source
- NIST NVD
- Note: Verify all details with official vendor sources before applying patches.
Affected Products
h3 : h3h3 : h3h3 : h3h3 : h3h3 : h3h3 : h3h3 : h3h3 : h3h3 : h3h3 : h3h3 : h3h3 : h3h3 : h3h3 : h3h3 : h3
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