CVE-2026-6324Public exploitNetwork attack vector

HTTP request smuggling via chunk-length conversion

Published May 29, 2026 · Updated May 29, 2026

HTTP request smuggling in libsoup allows remote attackers to bypass security controls through a crafted chunked HTTP request. soup_body_input_stream_read_chunked() converts an unsigned chunk length to a signed value, causing inconsistent parsing of the message body. Exploitation requires libsoup behind a non-libsoup proxy or in front of a non-libsoup backend, enabling cache poisoning or unauthorized access.

CVSS severity4.8
Medium
EPSS probability0.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP request smuggling in libsoup allows remote attackers to bypass security controls through a crafted chunked HTTP request. soup_body_input_stream_read_chunked() converts an unsigned chunk length to a signed value, causing inconsistent parsing of the message body. Exploitation requires libsoup behind a non-libsoup proxy or in front of a non-libsoup backend, enabling cache poisoning or unauthorized access.

The record

CVE
CVE-2026-6324
Published
May 29, 2026
Updated
May 29, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-444, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 29, 2026CVE publishedPublication date reported by the CVE source.
  2. May 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.8Red Hat, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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