CVE-2020-5669Network attack vector

Script execution via undisclosed SitemapNavigator input

Published Oct 26, 2021 · Updated Aug 4, 2024

Cross-site scripting in Movable Type Premium 1.37 and earlier allows remote authenticated users to run script in a logged-in user's browser. The flaw is in SitemapNavigator; Six Apart has not disclosed the affected input, rendering context, or missing neutralization operation. Exploitation requires access to submit crafted content and interaction by a logged-in victim, with resulting script execution in that victim's browser session.

CVSS severity6.1
Medium
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Movable Type Premium 1.37 and earlier allows remote authenticated users to run script in a logged-in user's browser. The flaw is in SitemapNavigator; Six Apart has not disclosed the affected input, rendering context, or missing neutralization operation. Exploitation requires access to submit crafted content and interaction by a logged-in victim, with resulting script execution in that victim's browser session.

The record

CVE
CVE-2020-5669
Published
Oct 26, 2021
Updated
Aug 4, 2024
Vendor
Six Apart Ltd.
Product
Movable Type
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 26, 2021CVE 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?

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

  1. Affected versionversion=Movable Type Premium 1.37 and earlier and Movable Type Premium Advanced 1.37 and earlier

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Six Apart Ltd. · Movable Typeversion=Movable Type Premium 1.37 and earlier and Movable Type Premium Advanced 1.37 and earlier

Published CVSS scores

3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
2.6JPCERT/CC JVNAV:N/AC:H/Au:N/C:N/I:P/A:N
6.1JPCERT/CC JVNCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/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.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

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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