Red Hat
CVE-2026-91920: 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 b
CVE-2026-91920 Oct 30, 2026 Source: Vendor
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.
Source of record
The credited names below are quoted verbatim from the vendor's own advisory:
https://nvd.nist.gov/vuln/detail/CVE-2026-91920
Are you credited here? Sign in to claim your line. It is yours immediately, with no review queue. The name the vendor printed stays next to your handle for anyone to check against the advisory above, and any member who thinks a claim is wrong can refute it.
Credited
1 line
Showing 1–1 of 1
CVE-2026-91920
BR2026-0000-039458
unclaimed
Credited as Red Hat would like to thank Arpit Jain for reporting this issue