Remote code execution via MIME-derived extension validation
Published Jul 17, 2026 · Updated Jul 17, 2026
Unrestricted file upload in CodeIgniter 4 before 4.7.3 allows remote attackers to execute code through a crafted upload. The ext_in rule in system/Validation/StrictRules/FileRules.php compares the MIME-derived guessed extension with its allowlist instead of checking the client filename extension. Exploitation requires an application to preserve the supplied filename in a web-accessible, script-enabled upload directory; the default application exposes no such endpoint.
Summary
What happened
Unrestricted file upload in CodeIgniter 4 before 4.7.3 allows remote attackers to execute code through a crafted upload. The ext_in rule in system/Validation/StrictRules/FileRules.php compares the MIME-derived guessed extension with its allowlist instead of checking the client filename extension. Exploitation requires an application to preserve the supplied filename in a web-accessible, script-enabled upload directory; the default application exposes no such endpoint.
The record
- CVE
- CVE-2026-48062
- Published
- Jul 17, 2026
- Updated
- Jul 17, 2026
- Vendor
- CodeIgniter Foundation
- Product
- CodeIgniter 4
- Classifications
- CWE-434, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 17, 2026CVE publishedPublication date reported by the CVE source.
- Jul 17, 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=< 4.7.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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