CVE-2026-48777

Description

FileBrowser Quantum: Path traversal in public share PATCH allows file ops outside shared directory

Description (MITRE) cveawg.mitre.org

Pulled from cveawg.mitre.org/api/cve/CVE-2026-48777 on 2026-07-27. Shown when MITRE's text differs from the cvelistV5 mirror.

FileBrowser Quantum is a free, self-hosted, web-based file manager. Versions prior to 1.3.2-stable, 1.4.0-beta and 1.4.1-beta are vulnerable to Path Traversal through the publicPatchHandler in backend/http/public.go which joins user-controlled fromPath and toPath body fields with the trusted d.share.Path BEFORE the downstream sanitizer runs. Because filepath.Join collapses .. segments during the join, the sanitizer in resourcePatchHandler never sees the traversal and the move/copy/rename operates on a path outside the shared directory. The same root-cause pattern was patched for the bulk DELETE endpoint as CVE-2026-44542 (GHSA-fwj3-42wh-8673), but the PATCH handler with the identical pattern was not updated. A public share link with AllowModify=true is sufficient to exploit this. Anyone holding such a link can move, copy, or rename arbitrary files within the share owner's source root. This issue has been fixed in versions 1.3.3-stable and 1.4.2-beta.

Overview

State

—

Assigner (CNA)

—

CVSS severity

high

CVSS score

7.5 / 10

CVSS vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Effective score

7.5 / 10 HIGH source: CNA overview

CWE(s)

—

Reserved

—

Published

—

Last updated

—

Source

https://www.tenable.com/cve/CVE-2026-48777

Linked Threat

CVE-2026-48777 — CVE-2026-48777

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published

2026-06-16 20:16:46 UTC

NVD last modified

2026-06-17 15:16:59 UTC

EPSS score

0.0045 (probability of exploitation in next 30 days)

EPSS percentile

36.48% vs all CVEs — higher = more likely to be exploited, as of 2026-07-27

NVD-assigned CWE(s): CWE-22 (differs from the CNA list above)

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID

EUVD-2026-37207

Assigner

GitHub_M

Published

Jun 16, 2026, 6:40:06 PM

Updated

Jun 17, 2026, 2:45:51 PM

EUVD base score (CVSS 4.0)

9.3 / 10
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

EUVD-reported EPSS

0.4500

Vendors

gtsteffaniak

Products

filebrowser (< 1.3.3-stable)

filebrowser (1.4.0-beta, < 1.4.2-beta)

Aliases

GHSA-qqqm-5547-774x

ENISA description: FileBrowser Quantum is a free, self-hosted, web-based file manager. Versions prior to 1.3.2-stable, 1.4.0-beta and 1.4.1-beta are vulnerable to Path Traversal through the publicPatchHandler in backend/http/public.go which joins user-controlled fromPath and toPath body fields with the trusted d.share.Path BEFORE the downstream sanitizer runs. Because filepath.Join collapses .. segments during the join, the sanitizer in resourcePatchHandler never sees the traversal and the move/copy/rename operates on a path outside the shared directory. The same root-cause pattern was patched for the bulk DELETE endpoint as CVE-2026-44542 (GHSA-fwj3-42wh-8673), but the PATCH handler with the identical pattern was not updated. A public share link with AllowModify=true is sufficient to exploit this. Anyone holding such a link can move, copy, or rename arbitrary files within the share owner's source root. This issue has been fixed in versions 1.3.3-stable and 1.4.2-beta.

Vendor references (0)

References embedded in the original CVE record by the assigning CNA.

None in the CVE record.

MITRE references (3) cveawg.mitre.org

Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.

• https://github.com/gtsteffaniak/filebrowser/releases/tag/v1.3.3-stable x_refsource_MISC
• https://github.com/gtsteffaniak/filebrowser/releases/tag/v1.4.2-beta x_refsource_MISC
• https://github.com/gtsteffaniak/filebrowser/security/advisories/GHSA-qqqm-5547-774x x_refsource_CONFIRM

Web references (2)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

• https://nvd.nist.gov/vuln/detail/CVE-2026-48777 tenable:nvd.nist.gov
• https://www.cve.org/CVERecord?id=CVE-2026-48777 tenable:www.cve.org

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

• CVE-2026-48777 - Overview, Insights & Trends
  web:cvemon.intruder.io

  Get the latest on CVE-2026-48777 , including risk score and recommendations. Vulnerability intelligence on trending CVEs from multiple sources.

  2026-06-19 02:25 UTC
• Nvd - Cve-2026-48777
  web:nvd.nist.gov

  An official website of the United States government Here's how you know

  2026-06-19 02:25 UTC
• Security Update Guide - Loading - Microsoft
  web:portal.msrc.microsoft.com

  The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

  2026-06-19 02:25 UTC
• CVE-2026-48777 - vulmon.com
  web:vulmon.com

  This same vulnerability pattern was previously addressed for the bulk DELETE endpoint in CVE - 2026 -44542 (GHSA-fwj3-42wh-8673), but the identical flaw in the PATCH handler remained unpatched.

  2026-06-19 02:25 UTC
• Microsoft is working on a patch for 'YellowKey ... - Computerworld
  web:www.computerworld.com

  Microsoft says it is considering a patch for a zero-day vulnerability, dubbed YellowKey, that allows attackers with access to a Windows device to bypass Bitlocker encryption protection and read ...

  2026-06-19 02:25 UTC
• May 2026 Patch Tuesday: Updates and Analysis | CrowdStrike
  web:www.crowdstrike.com

  Microsoft has released security updates for 130 vulnerabilities, including 30 critical, in its May 2026 Patch Tuesday rollout.

  2026-06-19 02:25 UTC
• Microsoft Technical Security Notifications
  web:www.microsoft.com

  Security Update Guide Notifications Microsoft's free Security Update Guide Notifications provide links to security-related software updates and notification of re-released security updates. These notifications are sent via email throughout the month as needed.

  2026-06-19 02:25 UTC
• Oracle Critical Security Patch Update Advisory - May 2026
  web:www.oracle.com

  This Critical Security Patch Update contains 35 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Security Patch Update and other Oracle Software Security Assurance activities is located at May 2026 Critical Security Patch Update: Executive Summary and Analysis.

  2026-06-19 02:25 UTC
• Patch Tuesday - June 2026 - Rapid7
  web:www.rapid7.com

  Microsoft is publishing 200 vulnerabilities on June 2026 Patch Tuesday, including an HTTP/2 denial of service vulnerability and an elevation of privilege vulnerability in PowerToys.

  2026-06-19 02:25 UTC
• Patch Tuesday June 2026: Security Updates & CVE Analysis
  web:zecurit.com

  Get the complete breakdown of Microsoft's June 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

  2026-06-19 02:25 UTC

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