CVE-2026-85534
MEDIUM
NVD
CVSS Score
5.9
Severity
MEDIUM
Published
Sep 04, 2026
Vendor
unknown
Description
A flaw was found in libsoup. When a client sends an HTTP/2 request body from a non-pollable input stream, the library can buffer more data than the current flow-control window later allows. A malicious HTTP/2 server can shrink SETTINGS_INITIAL_WINDOW_SIZE while that buffered read is still in progress. The client then copies the full buffer into a smaller DATA callback without a runtime bounds check, which can abort the process or fail the HTTP/2 session.