CVE-2021-32796Network attack vector

XML syntax alteration via unescaped namespace attributes

Published Jul 27, 2021 · Updated Aug 3, 2024

Improper output encoding in xmldom 0.6.0 and earlier allows remote attackers to alter serialized XML syntax through crafted input. XMLSerializer emits inherited namespace attribute values without escaping characters such as less-than, ampersand, and quotation marks when detached elements are serialized. Exploitation requires a downstream application to process attacker-influenced XML and serialize the detached element; the consequence is syntactic XML changes rather than direct code execution.

CVSS severity5.3
Medium
EPSS probability1.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper output encoding in xmldom 0.6.0 and earlier allows remote attackers to alter serialized XML syntax through crafted input. XMLSerializer emits inherited namespace attribute values without escaping characters such as less-than, ampersand, and quotation marks when detached elements are serialized. Exploitation requires a downstream application to process attacker-influenced XML and serialize the detached element; the consequence is syntactic XML changes rather than direct code execution.

The record

CVE
CVE-2021-32796
Published
Jul 27, 2021
Updated
Aug 3, 2024
Vendor
xmldom
Product
xmldom
Classifications
CWE-116, CWE-91
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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=< 0.7.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

xmldom · xmldomversion=< 0.7.0

Published CVSS scores

5.0NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
6.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-116Improper Encoding or Escaping of Output
CWE-91XML Injection (aka Blind XPath Injection)

Public exploit references

No public exploit references are available in this record.

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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