CVE-2026-21857Public exploitNetwork attack vector

Authenticated file disclosure via unchecked export directory

Published Jan 7, 2026 · Updated Jan 7, 2026

Path traversal in REDAXO Core before 5.20.2 allows remote authenticated users with backup permission to read files within the webroot. The Backup add-on's export.php accepts the EXPDIR POST value outside its UI allowlist, and backup.php concatenates that unchecked value with the base path when building a tar.gz archive. Backup permission is required; traversal or absolute paths can place readable configuration files, including database credentials and password hashes, into the downloaded archive.

CVSS severity8.3
High
EPSS probability0.54%
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 REDAXO Core before 5.20.2 allows remote authenticated users with backup permission to read files within the webroot. The Backup add-on's export.php accepts the EXPDIR POST value outside its UI allowlist, and backup.php concatenates that unchecked value with the base path when building a tar.gz archive. Backup permission is required; traversal or absolute paths can place readable configuration files, including database credentials and password hashes, into the downloaded archive.

The record

CVE
CVE-2026-21857
Published
Jan 7, 2026
Updated
Jan 7, 2026
Vendor
REDAXO
Product
REDAXO Core
Classifications
CWE-24, CWE-22, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 7, 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=< 5.20.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

REDAXO · REDAXO Coreversion=< 5.20.2

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
8.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-24Path Traversal: '../filedir'
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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