Arbitrary file write via PHAR deserialization
Published Jan 2, 2026 · Updated Jan 2, 2026
Deserialization in PluXml 5.8.22 and earlier allows remote authenticated users to write arbitrary files through the media manager. The rename path in core/admin/medias.php passes an attacker-controlled oldname value to is_readable and is_file, triggering PHAR metadata deserialization; FileCookieJar::__destruct then saves controlled cookie data with file_put_contents. Backend access and an uploaded PHAR disguised as an image are required, and the demonstrated chain writes a PHP web shell to an attacker-selected absolute path.
Summary
What happened
Deserialization in PluXml 5.8.22 and earlier allows remote authenticated users to write arbitrary files through the media manager. The rename path in core/admin/medias.php passes an attacker-controlled oldname value to is_readable and is_file, triggering PHAR metadata deserialization; FileCookieJar::__destruct then saves controlled cookie data with file_put_contents. Backend access and an uploaded PHAR disguised as an image are required, and the demonstrated chain writes a PHP web shell to an attacker-selected absolute path.
The record
- CVE
- CVE-2025-15438
- Published
- Jan 2, 2026
- Updated
- Jan 2, 2026
- Vendor
- PluXml
- Product
- PluXml
- Classifications
- CWE-502, CWE-20, T1190
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Jan 2, 2026CVE publishedPublication date reported by the CVE source.
- Jan 2, 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.
- Affected versionversion=5.8.0
- Affected versionversion=5.8.1
- Affected versionversion=5.8.10
- Affected versionversion=5.8.11
- Affected versionversion=5.8.12
- Affected versionversion=5.8.13
- Affected versionversion=5.8.14
- Affected versionversion=5.8.15
- Affected versionversion=5.8.16
- Affected versionversion=5.8.17
- Affected versionversion=5.8.18
- Affected versionversion=5.8.19
- Affected versionversion=5.8.2
- Affected versionversion=5.8.20
- Affected versionversion=5.8.21
- Affected versionversion=5.8.22
- Affected versionversion=5.8.3
- Affected versionversion=5.8.4
- Affected versionversion=5.8.5
- Affected versionversion=5.8.6
- Affected versionversion=5.8.7
- Affected versionversion=5.8.8
- Affected versionversion=5.8.9
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- PluXml CMS 5.8.22 Backend Deserialization Vulnerabilityfunctional · demonstrated
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Technologies
Your stack
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Your stack
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