CVE-2020-11535Network attack vector

Unauthenticated code execution via x2t XML injection

Published Apr 15, 2020 · Updated Aug 4, 2024

XML injection in ONLYOFFICE Document Server 5.5.0 allows remote attackers to execute code by submitting a crafted DOCX file. During conversion, x2t accepts an attacker-controlled parameter injected through document XML and uses it to overwrite its executable or libxcb.so.1. No authentication or user interaction is required; successful exploitation runs code on the document server.

CVSS severity9.8
Critical
EPSS probability2.32%
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 ONLYOFFICE Document Server 5.5.0 allows remote attackers to execute code by submitting a crafted DOCX file. During conversion, x2t accepts an attacker-controlled parameter injected through document XML and uses it to overwrite its executable or libxcb.so.1. No authentication or user interaction is required; successful exploitation runs code on the document server.

The record

CVE
CVE-2020-11535
Published
Apr 15, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-91, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 15, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

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

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 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 exploitUnconfirmed

Weakness, pattern, technique

CWE-91XML Injection (aka Blind XPath Injection)
T1190Exploit Public-Facing Application

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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