CVE-2021-47783Public exploitNetwork attack vectorHinoki check available

Stored XSS via script-bearing SVG upload

Published Jan 15, 2026 · Updated Jan 15, 2026

Stored XSS in phpwcms 1.9.30 allows remote authenticated users to execute JavaScript in another user's browser via an SVG upload. The multiple file upload feature accepts an SVG containing an embedded script and serves the file from the web-accessible upload directory without neutralizing its active content. Backend access is required to upload the payload, and another user must open the stored SVG; execution is limited to that user's browser context.

CVSS severity5.3
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Stored XSS in phpwcms 1.9.30 allows remote authenticated users to execute JavaScript in another user's browser via an SVG upload. The multiple file upload feature accepts an SVG containing an embedded script and serves the file from the web-accessible upload directory without neutralizing its active content. Backend access is required to upload the payload, and another user must open the stored SVG; execution is limited to that user's browser context.

The record

CVE
CVE-2021-47783
Published
Jan 15, 2026
Updated
Jan 15, 2026
Vendor
phpwcms
Product
phpwcms
Classifications
CWE-434, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 15, 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=1.9.30

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

phpwcms · phpwcmsversion=1.9.30

Published CVSS scores

5.4VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
5.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA: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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1059.007JavaScript/JScript

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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