Unrestricted File Upload in codeigniter4/framework (CVE-2026-63223)
Summary
Vulnerability in codeigniter4/framework (CVE-2026-63223). Successful exploitation can lead to full system takeover. Exploitable via is_image. Mitigation: upgrade to 4.7.4 or later.
Original description
The description as published by the source.
Impact
This is an unsafe file upload validation vulnerability that can lead to remote code execution in vulnerable application configurations.
Applications are impacted when they:
- validate uploads using
is_imageormime_inwithout an independent safe extension check, such asext_inon patched versions - save uploaded files using the client-supplied filename
- place uploads in a web-accessible directory where PHP files can execute
Patches
Upgrade to v4.7.4 or later.
Workarounds
- Save uploads outside the public web root, preferably under
writable/uploads. - Use
$file->store()or$file->move($path, $file->getRandomName())instead of preserving the original client filename. - Disable script execution in any public upload directory.
- Manually verify the client filename extension before moving the file.
- For image uploads, reject files when
$file->getClientExtension()is not an allowed image extension. - For exact MIME-type validation, reject files when
$file->getClientExtension()does not match$file->guessExtension().
Source: NIST National Vulnerability Database 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-2026-63223 has been found in codeigniter4/framework.
Attackers can target a specific entry point like is_image 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 4.7.4 or later.
If unsure, ask your IT team or search "codeigniter4/framework CVE-2026-63223" on the vendor's site.
CVE-2026-63223 (codeigniter4/framework) — CWE-434 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: is_image / mime_in / ext_in
Patched: 4.7.4 — 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 is_image without authentication.
Check the vendor advisory for the affected versions of codeigniter4/framework. Attack surface: is_image / mime_in / ext_in.
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.
Update to 4.7.4.
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
-
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 4.7.4ステージング環境で 4.7.4 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
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2026-63223 php-codeigniter-framework
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com