CVE-2026-30934Public exploitNetwork attack vector

Stored XSS via unescaped share metadata

Published Mar 10, 2026 · Updated Mar 10, 2026

Stored XSS in FileBrowser Quantum before 1.2.2-stable or 1.3.1-beta allows remote authenticated users to execute scripts via share metadata. The public share renderer uses text/template rather than html/template, placing persistent title and description values into HTML without contextual escaping. A user with share-creation permission must store the payload and induce a victim to open the share URL, where it runs in the application origin.

CVSS severity8.9
High
EPSS probability0.35%
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 FileBrowser Quantum before 1.2.2-stable or 1.3.1-beta allows remote authenticated users to execute scripts via share metadata. The public share renderer uses text/template rather than html/template, placing persistent title and description values into HTML without contextual escaping. A user with share-creation permission must store the payload and induce a victim to open the share URL, where it runs in the application origin.

The record

CVE
CVE-2026-30934
Published
Mar 10, 2026
Updated
Mar 10, 2026
Vendor
Graham Steffaniak
Product
FileBrowser Quantum
Classifications
CWE-79, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.2.2-stable
  2. Affected versionversion=>= 1.3.0-beta, < 1.3.1-beta

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Graham Steffaniak · FileBrowser Quantumversion=< 1.2.2-stable; version=>= 1.3.0-beta, < 1.3.1-beta

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
8.9GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L

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 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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

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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