CVE-2026-25891Public exploitNetwork attack vector

Arbitrary file read via double-decoded backslashes

Published Feb 24, 2026 · Updated Feb 24, 2026

Path traversal in GoFiber Fiber 3.0.0 allows remote attackers to read arbitrary server files through Windows static middleware. The sanitizePath function checks for backslashes before repeatedly URL-decoding the request path, then applies path.Clean, which does not treat backslashes as separators. Exploitation requires a Windows-hosted application using Fiber's static middleware and yields reads within the server process's filesystem permissions.

CVSS severity8.7
High
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in GoFiber Fiber 3.0.0 allows remote attackers to read arbitrary server files through Windows static middleware. The sanitizePath function checks for backslashes before repeatedly URL-decoding the request path, then applies path.Clean, which does not treat backslashes as separators. Exploitation requires a Windows-hosted application using Fiber's static middleware and yields reads within the server process's filesystem permissions.

The record

CVE
CVE-2026-25891
Published
Feb 24, 2026
Updated
Feb 24, 2026
Vendor
GoFiber
Product
Fiber
Classifications
CWE-22, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 24, 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=>= 3.0.0, < 3.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GoFiber · Fiberversion=>= 3.0.0, < 3.1.0

Published CVSS scores

7.7GitHub CNACVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
8.7GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA: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.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System

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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