CVE-2026-66338EPSS p18.4%

CVE-2026-66338CVE-2026-66338

gnome / libsoup

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.

Scoring

CVSS 5.4 ()
VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS0.28% probability of exploitation · percentile 18.4% · 2026-10-06T12:00:23Z
Last modified2026-08-24
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.