PT-2026-64427 · Red Hat · Red Hat Enterprise Linux 10+4

CVE-2026-66338 · Published 2026-07-24 · Updated 2026-07-24

NVD

CVSS v3.1

5.4

Medium

Base vector

AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

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.

Fix

HTTP Request/Response Smuggling

Weakness Enumeration

CWE-444

Related Identifiers

CVE-2026-66338

Affected Products

Red Hat Enterprise Linux 10

Red Hat Enterprise Linux 6

Red Hat Enterprise Linux 7

Red Hat Enterprise Linux 8

Red Hat Enterprise Linux 9

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-66338 · Security Note
• https://access.redhat.com/security/cve/CVE-2026-66338 · Note
• https://bugzilla.redhat.com/show_bug.cgi?id=2506950 · Note