CVE-2026-66338

highpriority · track · 29EPSS 0.003 · 21 %ileEUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.29% (21st) EPSS
CVSS 7.2 · high
Is it mine?
6 products
Check your exposure
Who says so?
3 sources
cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-23

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.

01

cvss

Technical severity, 0–10. One row per scoring source.

7.2
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.4–7.2

v3.17.2highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 2.7
v3.15.4mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:Nsecondary · ENISA EU
v3.15.4mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:Nsecondary · secalert@redhat.com USexploitability 2.2 · impact 2.7
v3.16.6mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-444US
04

affected products (6)

Products and version ranges known to be affected.

05

also known as (3)

Other names and identifiers for this entity.

06

sources

Which sources assert this record, and when.

cnnvdenisa_euvdnvdNVDCVE.orgMITRE
published 2026-07-24modified 2026-08-24
07

references (6)

External citations — patches, advisories, analysis.

scry

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