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CVE PROGRAM SOURCE RECORD5.4 Medium

CVE-2026-66338

Libsoup: libsoup: http request smuggling via permissive chunk-size parsing in soup_body_input_stream_read_chunked()

Description

A flaw was found in libsoup. The chunked transfer encoding parser uses a permissive parsing function for chunk sizes that silently accepts inputs violating RFC 9112, including leading whitespace, plus sign prefixes, and trailing invalid characters. When libsoup operates behind a strict frontend proxy, this parsing differential can be exploited to smuggle HTTP requests.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Red Hat Red Hat Enterprise Linux 10

Default version status: affected

Red Hat Red Hat Enterprise Linux 6

Default version status: affected

Red Hat Red Hat Enterprise Linux 7

Default version status: affected

Red Hat Red Hat Enterprise Linux 8

Default version status: affected

Red Hat Red Hat Enterprise Linux 9

Default version status: affected

References