MEDIUMCVSS 6.9
CVE-2026-86252
CVE-2026-86252 updated by NVD
Summary
h3 versions before 1.15.9 fail to sanitize carriage return characters in EventStream data and comment fields, allowing attackers to inject arbitrary SSE events by including unsanitized carriage returns. Attackers can inject event type directives, split single push calls into multiple browser-parsed events, or escape comment fields to inject data, bypassing the prior CVE fix that only addressed newline injection.
References
Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.
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