CVE-2026-9390Network attack vector

Signed-node substitution via XPath-injected ID lookup

Published Aug 3, 2026 · Updated Aug 3, 2026

XPath injection in XML::Sig before 0.71 allows attackers to redirect XML signature ID lookups through a crafted Reference URI. XML::Sig::verify and _get_signed_xml concatenate the URI into an XPath string without escaping it or enforcing the ID character grammar. Applications that verify signed XML supplied by remote attackers expose digest selection to the injected expression, including unintended or all nodes.

CVSS severity9.1
Critical
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XPath injection in XML::Sig before 0.71 allows attackers to redirect XML signature ID lookups through a crafted Reference URI. XML::Sig::verify and _get_signed_xml concatenate the URI into an XPath string without escaping it or enforcing the ID character grammar. Applications that verify signed XML supplied by remote attackers expose digest selection to the injected expression, including unintended or all nodes.

The record

CVE
CVE-2026-9390
Published
Aug 3, 2026
Updated
Aug 3, 2026
Vendor
Timothy Legge
Product
XML::Sig
Classifications
CWE-1287, CWE-643, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=0 <0.71

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Timothy Legge · XML::Sigversion=0 <0.71

Published CVSS scores

9.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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-1287Improper Validation of Specified Type of Input
CWE-643Improper Neutralization of Data within XPath Expressions ('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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