Unrestricted File Upload in codeigniter4/framework (CVE-2026-48062)
Summary
Vulnerability in codeigniter4/framework (CVE-2026-48062). Successful exploitation can lead to full system takeover. Exploitable via ext_in. Mitigation: upgrade to 4.7.3 or later.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-48062 has been found in codeigniter4/framework.
Attackers can target a specific entry point like ext_in over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: upgrade codeigniter4/framework to 4.7.3 or later.
If unsure, ask your IT team or search "codeigniter4/framework CVE-2026-48062" on the vendor's site.
CVE-2026-48062 (codeigniter4/framework) — CWE-434 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: ext_in / shell.php / gif / php
Patched: 4.7.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-434) exists in codeigniter4/framework. Attackers reach the vulnerable code path via ext_in without authentication.
Check the vendor advisory for the affected versions of codeigniter4/framework. Attack surface: ext_in / shell.php / gif / php.
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.
Update to 4.7.3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'codeigniter4/framework' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'codeigniter4/framework' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
codeigniter4/frameworkを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade codeigniter4/framework to 4.7.3ステージング環境で 4.7.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- web codeigniter.com
- web codeigniter.com
- web github.com
- web github.com
- web github.com