Unauthenticated code execution via upload extension mismatch
Published Jul 31, 2026 · Updated Jul 31, 2026
Unsafe file upload validation in CodeIgniter 4 before 4.7.4 allows remote attackers to execute PHP through crafted uploads. The is_image rule trusts a content-derived image MIME type, while mime_in compares MIME content but neither rejects a dangerous client filename extension. Exploitation requires an application to preserve that filename and store the upload in a web-accessible directory where PHP execution is enabled.
Summary
What happened
Unsafe file upload validation in CodeIgniter 4 before 4.7.4 allows remote attackers to execute PHP through crafted uploads. The is_image rule trusts a content-derived image MIME type, while mime_in compares MIME content but neither rejects a dangerous client filename extension. Exploitation requires an application to preserve that filename and store the upload in a web-accessible directory where PHP execution is enabled.
The record
- CVE
- CVE-2026-63223
- Published
- Jul 31, 2026
- Updated
- Jul 31, 2026
- Vendor
- CodeIgniter Foundation
- Product
- CodeIgniter 4
- Classifications
- CWE-434, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 31, 2026CVE publishedPublication date reported by the CVE source.
- Jul 31, 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=< 4.7.4
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
- CVE-2026-63223 CodeIgniter file-upload RCE proof of conceptproof of concept · unverified
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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