CVE-2023-4520Network attack vector

Stored XSS and user-meta modification via unsanitized save

Published Aug 25, 2023 · Updated Apr 8, 2026

Stored XSS and user-meta update in FV Flowplayer Video Player 7.5.37.7212 and earlier allow remote attackers to inject scripts and alter metadata. The init-hooked save function accepts the _fv_player_user_video parameter without sufficient sanitization, stores it, renders it without sufficient escaping, and permits arbitrary string-valued user-meta updates. Unauthenticated network access is sufficient; a later page view executes the stored script in that visitor's browser, while the companion flaw can modify user metadata only with string values.

CVSS severity5.4
Medium
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS and user-meta update in FV Flowplayer Video Player 7.5.37.7212 and earlier allow remote attackers to inject scripts and alter metadata. The init-hooked save function accepts the _fv_player_user_video parameter without sufficient sanitization, stores it, renders it without sufficient escaping, and permits arbitrary string-valued user-meta updates. Unauthenticated network access is sufficient; a later page view executes the stored script in that visitor's browser, while the companion flaw can modify user metadata only with string values.

The record

CVE
CVE-2023-4520
Published
Aug 25, 2023
Updated
Apr 8, 2026
Vendor
FolioVision
Product
FV Flowplayer Video Player
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 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=0 <=7.5.37.7212

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FolioVision · FV Flowplayer Video Playerversion=0 <=7.5.37.7212

Published CVSS scores

5.4WordfenceCVSS:3.1/AV:N/AC:H/PR:N/UI:N/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
Privilegesunauthenticated
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.

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Technologies

Your stack

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Your stack

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