CVE-2026-44453 (GCVE-0-2026-44453)
Vulnerability from cvelistv5
Published
2026-07-16 23:04
Modified
2026-07-17 14:29
CWE
  • CWE-789 - Memory Allocation with Excessive Size Value
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Summary
h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit 6b5370d, h2o is vulnerable to a Denial of Service attack when calling alloca under certain conditions. When serving static files, h2o builds the file path on stack, by calling alloca. The maximum size of the memory allocated using alloca can be as huge as ~600KB, which exceeds the default pthread stack size used by musl libc (128KB). If the amount of memory allocated by alloca exceeds the stack size, the h2o server crashes with a segmentation fault, while it tries to touch the guard page. This issue has been fixed by commit 6b5370d.
Impacted products
Vendor Product Version
h2o h2o Version: < 6b5370d
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Show details on NVD website


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
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