Vulnerability-Lookup

GHSA-R633-FCGP-M532

Vulnerability from github – Published: 2026-03-09 19:48 – Updated: 2026-03-24 21:09

Summary

FileBrowser Quantum: Stored XSS in public share page via unsanitized share metadata (text/template misuse)

Details

Summary

Stored XSS is possible via share metadata fields (e.g., title, description) that are rendered into HTML for /public/share/<hash> without context-aware escaping. The server uses text/template instead of html/template, allowing injected scripts to execute when victims visit the share URL.

Details

The server renders public/index.html using text/template and injects user-controlled share fields (title/description/etc.) into HTML contexts. text/template does not perform HTML contextual escaping like html/template. Because share metadata is persistent, the payload becomes stored and executes whenever a victim opens the affected share page.

Relevant code paths: - backend/http/static.go (template rendering and share metadata assignment) - backend/http/httpRouter.go (template initialization) - frontend/public/index.html (insertion points for title/description and related fields)

PoC

Login as a user with share creation permission.
Create a share (POST /api/share) with malicious metadata:
title = </title><script>alert("xss")</script><title>
Open the resulting /public/share/<hash> URL in a browser.
Expected: Payload is safely escaped and displayed as text.
Actual: JavaScript executes in victim's browser (stored XSS).

Tested on Docker image: gtstef/filebrowser:stable (version v1.2.1-stable).

Impact

Arbitrary script execution in application origin.
Potential account/session compromise, CSRF-like action execution, data exfiltration from authenticated contexts.
Affects anyone (including unauthenticated visitors) opening the malicious share URL.
The XSS is stored and persistent — no social engineering beyond sharing the link is required.

Severity

8.9 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/gtsteffaniak/filebrowser"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.0.0-20260307130210-09713b32a5f6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-30934"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-09T19:48:15Z",
    "nvd_published_at": "2026-03-10T18:18:53Z",
    "severity": "HIGH"
  },
  "details": "## Summary\nStored XSS is possible via share metadata fields (e.g., `title`, `description`) that are rendered into HTML for `/public/share/\u003chash\u003e` without context-aware escaping. The server uses `text/template` instead of `html/template`, allowing injected scripts to execute when victims visit the share URL.\n\n## Details\nThe server renders `public/index.html` using `text/template` and injects user-controlled share fields (title/description/etc.) into HTML contexts. `text/template` does not perform HTML contextual escaping like `html/template`. Because share metadata is persistent, the payload becomes stored and executes whenever a victim opens the affected share page.\n\nRelevant code paths:\n- `backend/http/static.go` (template rendering and share metadata assignment)\n- `backend/http/httpRouter.go` (template initialization)\n- `frontend/public/index.html` (insertion points for title/description and related fields)\n\n## PoC\n1. Login as a user with share creation permission.\n2. Create a share (`POST /api/share`) with malicious metadata:\n   - `title = \u003c/title\u003e\u003cscript\u003ealert(\"xss\")\u003c/script\u003e\u003ctitle\u003e`\n3. Open the resulting `/public/share/\u003chash\u003e` URL in a browser.\n4. **Expected:** Payload is safely escaped and displayed as text.\n5. **Actual:** JavaScript executes in victim\u0027s browser (stored XSS).\n\nTested on Docker image: `gtstef/filebrowser:stable` (version `v1.2.1-stable`).\n\n## Impact\n- Arbitrary script execution in application origin.\n- Potential account/session compromise, CSRF-like action execution, data exfiltration from authenticated contexts.\n- Affects anyone (including unauthenticated visitors) opening the malicious share URL.\n- The XSS is stored and persistent \u2014 no social engineering beyond sharing the link is required.",
  "id": "GHSA-r633-fcgp-m532",
  "modified": "2026-03-24T21:09:10Z",
  "published": "2026-03-09T19:48:15Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/gtsteffaniak/filebrowser/security/advisories/GHSA-r633-fcgp-m532"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-30934"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/gtsteffaniak/filebrowser"
    },
    {
      "type": "WEB",
      "url": "https://github.com/gtsteffaniak/filebrowser/releases/tag/v1.2.2-stable"
    },
    {
      "type": "WEB",
      "url": "https://github.com/gtsteffaniak/filebrowser/releases/tag/v1.3.1-beta"
    },
    {
      "type": "WEB",
      "url": "https://pkg.go.dev/vuln/GO-2026-4660"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "FileBrowser Quantum: Stored XSS in public share page via unsanitized share metadata (text/template misuse)"
}

CVE-2026-30934 (GCVE-0-2026-30934)

Vulnerability from cvelistv5 – Published: 2026-03-10 16:12 – Updated: 2026-03-10 16:41

Title

FileBrowser Quantum: Stored XSS in public share page via unsanitized share metadata (text/template misuse)

Summary

FileBrowser Quantum is a free, self-hosted, web-based file manager. Prior to 1.3.1-beta and 1.2.2-stable, Stored XSS is possible via share metadata fields (e.g., title, description) that are rendered into HTML for /public/share/<hash> without context-aware escaping. The server uses text/template instead of html/template, allowing injected scripts to execute when victims visit the share URL. This vulnerability is fixed in 1.3.1-beta and 1.2.2-stable.

Severity

8.9 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-10 16:38 UTC

CWE

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

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/gtsteffaniak/filebrowser/secur…	x_refsource_CONFIRM
https://github.com/gtsteffaniak/filebrowser/relea…	x_refsource_MISC
https://github.com/gtsteffaniak/filebrowser/relea…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
gtsteffaniak	filebrowser	Affected: >= 1.3.0-beta, < 1.3.1-beta Affected: < 1.2.2-stable

Show details on NVD website

JSON

To clipboard

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  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-30934",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-10T16:38:59.115847Z",
                "version": "2.0.3"
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
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          "product": "filebrowser",
          "vendor": "gtsteffaniak",
          "versions": [
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              "status": "affected",
              "version": "\u003e= 1.3.0-beta, \u003c 1.3.1-beta"
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          "value": "FileBrowser Quantum is a free, self-hosted, web-based file manager. Prior to 1.3.1-beta and 1.2.2-stable, Stored XSS is possible via share metadata fields (e.g., title, description) that are rendered into HTML for /public/share/\u003chash\u003e without context-aware escaping. The server uses text/template instead of html/template, allowing injected scripts to execute when victims visit the share URL. This vulnerability is fixed in 1.3.1-beta and 1.2.2-stable."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 8.9,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L",
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              "type": "CWE"
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        "shortName": "GitHub_M"
      },
      "references": [
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          "name": "https://github.com/gtsteffaniak/filebrowser/security/advisories/GHSA-r633-fcgp-m532",
          "tags": [
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          ],
          "url": "https://github.com/gtsteffaniak/filebrowser/security/advisories/GHSA-r633-fcgp-m532"
        },
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          "name": "https://github.com/gtsteffaniak/filebrowser/releases/tag/v1.2.2-stable",
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        "discovery": "UNKNOWN"
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      "title": "FileBrowser Quantum: Stored XSS in public share page via unsanitized share metadata (text/template misuse)"
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    "dateReserved": "2026-03-07T16:40:05.885Z",
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    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-R633-FCGP-M532

Summary

Details

PoC

Impact

CVE-2026-30934 (GCVE-0-2026-30934)

Tags

Sightings

Nomenclature

Related by attack behaviour