CVE-2026-55213
h2o h2o 취약점
h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit edd7a120bfc4af11ac0cbebce2a43cc1f93f9af1, when h2o processes a QPACK instruction sent from the peer over HTTP/3, lib/http3/qpack.c might allocate an on-stack buffer as large as approximately 800 KB by calling alloca, which exceeds the default pthread stack size used by musl libc and causes the h2o server to crash with a segmentation fault while touching the guard page. This issue is fixed in commit edd7a120bfc4af11ac0cbebce2a43cc1f93f9af1.
- 대응 우선순위
- 점검
- CVSS
- 7.5
- EPSS
- 0.34% 백분위 27.0% · 2026.07.28 기준
- CISA KEV
- 미등록
- 조치 기한
- -
- 공개일
- 2026.07.11