Vulnerability in getgrav/grav (CVE-2026-59193)
Summary
Vulnerability in getgrav/grav (CVE-2026-59193). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 2.0.0 or later.
Original description
The description as published by the source.
Summary
An authenticated admin.super user can crash Grav or fill the disk by uploading a specially crafted ZIP archive through the Direct Install tool. The method Installer::unZip() calls ZipArchive::extractTo() without any limit on uncompressed size, entry count, or directory depth, enabling Zip Bomb (CWE-409), stack overflow (CWE-674), and disk/inode exhaustion.
Details
The vulnerability is in system/src/Grav/Common/GPM/Installer.php:176-208 (Installer::unZip()). The ZipArchive::extractTo() call at line 184 is not preceded by any validation of the archive contents.
Missing validation:
- ❌ No total uncompressed size check (decompression bomb — CWE-409)
- ❌ No entry count check (inode exhaustion)
- ❌ No directory nesting depth check (stack overflow in
Folder::doDelete()— CWE-674)
The subsequent cleanup call Folder::delete($destination) at line 189 recursively deletes every subdirectory without depth limit (Folder.php:531-547). A ZIP with thousands of nested directories will cause PHP's maximum nesting level to be exceeded, so the cleanup fails silently and leaves extracted files on disk.
The existing Zip Slip fix (GHSA-w48r-jppp-rcfw / CVE-2026-42607, commit 5a12f9be8) only checks for ../ in entry paths and does not add any size, count, or depth limits.
PoC
-
Generate the malicious ZIP:
python3 cve_poc_grav_zip.py:
#!/usr/bin/env python3
"""
CVE PoC — Grav CMS Installer::unZip()
Zip Bomb + Zip Slip + Deep Nesting
ZIP file to…
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-2026-59193 has been found in getgrav/grav.
Risk of unauthorized operations or information disclosure. CVSS score: 4.9/10.
What to do: upgrade getgrav/grav to 2.0.0 or later.
If unsure, ask your IT team or search "getgrav/grav CVE-2026-59193" on the vendor's site.
CVE-2026-59193 (getgrav/grav) — CWE-409 / CVSS v3 4.9
Attack vector: remote (network-reachable) / no user interaction
Patched: 2.0.0 — 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-409) exists in getgrav/grav.
Check the vendor advisory for the affected versions of getgrav/grav.
Severity: Medium (CVSS 4.9/10). Risk of unauthorized operations or information disclosure.
Update to 2.0.0.
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 'getgrav/grav' . 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 'getgrav/grav' . | 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
getgrav/grav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 getgrav/grav to 2.0.0ステージング環境で 2.0.0 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
- web github.com
- web github.com
- web github.com
- web nvd.nist.gov
- web github.com