CVE-2019-20204Public exploitNetwork attack vector

Stored script execution via unsanitized SVG polyglot

Published Jan 1, 2020 · Updated Aug 5, 2024

Stored XSS in Postie 1.9.40 for WordPress allows remote authenticated users to execute script in a post viewer's browser. The email-to-post path accepts a mixed-case JavaScript polyglot with a crafted SVG element and stores it as executable post content without neutralization. An authorized sender must submit the crafted content and a user must view the resulting post, allowing script execution in that viewer's WordPress origin.

CVSS severity5.4
Medium
EPSS probability3.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Postie 1.9.40 for WordPress allows remote authenticated users to execute script in a post viewer's browser. The email-to-post path accepts a mixed-case JavaScript polyglot with a crafted SVG element and stores it as executable post content without neutralization. An authorized sender must submit the crafted content and a user must view the resulting post, allowing script execution in that viewer's WordPress origin.

The record

CVE
CVE-2019-20204
Published
Jan 1, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 1, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/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 exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

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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