CVE-2026-48062 | CodeIgniter: Uploaded file extension validation bypass in `ext_in` rule

CodeIgniter is a PHP full-stack web framework. Prior to 4.7.3, the ext_in upload validation rule in system/Validation/StrictRules/FileRules.php checked the MIME-derived guessed extension instead of the client-provided filename extension. As a result, an uploaded file named shell.php containing GIF-like content could pass validation such as uploaded[avatar]|is_image[avatar]|mime_in[avatar,image/gif]|ext_in[avatar,gif] because the detected MIME type maps to gif, even though the uploaded filename extension is php. Applications are impacted if they accept user-controlled uploads, rely on ext_in to validate the uploaded filename extension, save uploaded files using the original client filename with $file->move($path), store uploads in a web-accessible directory, and allow PHP or other executable files to run from that directory. In those conditions, this may lead to arbitrary code execution. This issue is fixed in version 4.7.3.

Published: 2026-07-17 Last update: 2026-07-23 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-48062 is rated Moderate Risk (52.1/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.44%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-48062

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-07-18 0.08% 0.44% +0.37%
2 2026-06-12 — 0.08% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-48062

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2026-48062

GitHub Security Advisory for CVE-2026-48062

GHSA-2gr4-ppc7-7mhx · Severity: critical · Ecosystem: composer — CodeIgniter4 has a validation bypass when uploading file extensions via `ext_in` rule

Affected software / configurations for CVE-2026-48062

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-48062

cvelogic Threat Intelligence