CVE-2026-27147Public exploitNetwork attack vector

Stored XSS via permissive SVG upload validation

Published Feb 20, 2026 · Updated Feb 20, 2026

Stored XSS in GetSimple CMS Community Edition 3.3.22 and earlier allows remote authenticated users to execute JavaScript via SVG uploads. The upload handler passes each file to validate_safe_file, whose MIME and extension blacklists omit SVG, then moves the unchanged file into the web-accessible uploads directory. Any authenticated account can store the payload; JavaScript runs in the application origin when another user opens the uploaded SVG, enabling actions in that user's browser session.

CVSS severity6.9
Medium
EPSS probability0.20%
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 GetSimple CMS Community Edition 3.3.22 and earlier allows remote authenticated users to execute JavaScript via SVG uploads. The upload handler passes each file to validate_safe_file, whose MIME and extension blacklists omit SVG, then moves the unchanged file into the web-accessible uploads directory. Any authenticated account can store the payload; JavaScript runs in the application origin when another user opens the uploaded SVG, enabling actions in that user's browser session.

The record

CVE
CVE-2026-27147
Published
Feb 20, 2026
Updated
Feb 20, 2026
Vendor
GetSimpleCMS-CE
Product
GetSimple CMS Community Edition
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 20, 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=<= 3.3.22

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GetSimpleCMS-CE · GetSimple CMS Community Editionversion=<= 3.3.22

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
6.9GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/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.

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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