CVE-2026-91920
MEDIUM
NVD
CVSS Score
6.5
Severity
MEDIUM
Published
Oct 30, 2026
Vendor
unknown
Description
A flaw was found in the ChunkReader component of the Undertow web server, which is used to handle chunked transfer encoding in HTTP requests. The issue occurs because a security check for the chunk size is performed before the value is shifted, allowing a specifically crafted 15-digit chunk size to bypass the limit and overflow into internal state flags. This can cause the server to terminate a request body prematurely and interpret the remaining data as a separate, smuggled request.