CVE-2025-56515Public exploitNetwork attack vector

Stored XSS via unsanitized SVG avatar upload

Published Oct 1, 2025 · Updated Oct 1, 2025

Stored XSS in Fiora 1.0.0 allows remote authenticated users to execute JavaScript in another user’s browser through a profile avatar. The changeUserAvatar path stores SVG avatar content without rejecting foreignObject, iframe, or JavaScript event-handler markup before Avatar renders it. Exploitation requires an account and another user to render or directly open the stored SVG, exposing that user’s session data and permitting actions in that user’s context.

CVSS severity8.8
High
EPSS probability0.52%
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 Fiora 1.0.0 allows remote authenticated users to execute JavaScript in another user’s browser through a profile avatar. The changeUserAvatar path stores SVG avatar content without rejecting foreignObject, iframe, or JavaScript event-handler markup before Avatar renders it. Exploitation requires an account and another user to render or directly open the stored SVG, exposing that user’s session data and permitting actions in that user’s context.

The record

CVE
CVE-2025-56515
Published
Oct 1, 2025
Updated
Oct 1, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, CWE-434, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 1, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 1, 2025Record 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

8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
2.0GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:P

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')
CWE-434Unrestricted Upload of File with Dangerous Type
T1059.007Command and Scripting Interpreter: JavaScript

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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