Out-of-bounds Read in GNOME Libsoup

CVE-2026-66337

A flaw was found in libsoup. An unsigned integer underflow in the soup_filter_input_stream_read_until() function causes a heap buffer over-read when parsing multipart HTTP responses. A malicious HTTP server can exploit this by sending a crafted multipart response, potentially causing the client application to crash or disclose sensitive heap memory.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (13.3th percentile) — read the EPSS interpretation.