CVE-2026-54089Public exploitNetwork attack vector

Unauthenticated account takeover via trusted proxy header

Published Jun 25, 2026 · Updated Jun 25, 2026

Authentication bypass in File Browser 2.0.0-rc.1 and later allows remote attackers to impersonate any user via a forged proxy header. ProxyAuth.Auth reads the configured identity header from any request without validating its source, returns the named user without a password check, and creates the account when it does not exist. Proxy authentication must be enabled and the service must be directly reachable; successful requests obtain a valid session, including administrator access.

CVSS severity9.1
Critical
EPSS probability0.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in File Browser 2.0.0-rc.1 and later allows remote attackers to impersonate any user via a forged proxy header. ProxyAuth.Auth reads the configured identity header from any request without validating its source, returns the named user without a password check, and creates the account when it does not exist. Proxy authentication must be enabled and the service must be directly reachable; successful requests obtain a valid session, including administrator access.

The record

CVE
CVE-2026-54089
Published
Jun 25, 2026
Updated
Jun 25, 2026
Vendor
File Browser Contributors
Product
File Browser
Classifications
CWE-287, CWE-290, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 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=>= 2.0.0-rc.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

File Browser Contributors · File Browserversion=>= 2.0.0-rc.1

Published CVSS scores

9.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
CWE-290Authentication Bypass by Spoofing
T1190Exploit Public-Facing Application

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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