CVE-2026-53723Network attack vector

XML injection via embedded CDATA terminator

Published Jun 11, 2026 · Updated Jun 11, 2026

XML injection in Guzzle Services before 1.5.4 allows remote attackers to alter outgoing XML request bodies through crafted element values. The XML request serializer passes reserved-character text to XMLWriter::writeCData without splitting an embedded CDATA terminator, so trailing input becomes markup. Exploitation requires untrusted text in a location: xml element parameter and a downstream service that acts on injected or duplicated elements.

CVSS severity5.8
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XML injection in Guzzle Services before 1.5.4 allows remote attackers to alter outgoing XML request bodies through crafted element values. The XML request serializer passes reserved-character text to XMLWriter::writeCData without splitting an embedded CDATA terminator, so trailing input becomes markup. Exploitation requires untrusted text in a location: xml element parameter and a downstream service that acts on injected or duplicated elements.

The record

CVE
CVE-2026-53723
Published
Jun 11, 2026
Updated
Jun 11, 2026
Vendor
Guzzle
Product
Guzzle Services
Classifications
CWE-20, CWE-91, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 11, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.5.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Guzzle · Guzzle Servicesversion=< 1.5.4

Published CVSS scores

5.8GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-91XML Injection (aka Blind XPath Injection)
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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