CVE-2021-26599 — impresscms/impresscms
CRITICALCVE-2021-26599 is a critical-severity (CVSS 9.8) SQL Injection vulnerability in impresscms/impresscms. 4 public exploit references exist, so weaponization risk is real. A fix is available for impresscms/impresscms — see the affected versions and patch details below.
SQL Injection in ImpressCMS
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2021-26599 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
impresscms/impresscmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
ImpressCMS before 1.4.3 allows include/findusers.php groups SQL Injection.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | impresscms/impresscms | all versions | 1.4.3composer require impresscms/impresscms:^1.4.3 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
ImpressCMS 1.4.2 - Remote Code Execution (RCE)
by Egidio Romano · Mar 30, 2022
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for impresscms/impresscms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update impresscms/impresscms to 1.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-26599 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2021-26599 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2021-26599. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect CVE-2021-26599
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2021-26599 -u https://target- Template
- ImpressCMS < 1.4.3 - SQL Injection
- Severity
- high
- Impact
- Unauthenticated attackers can execute arbitrary SQL queries via SQL injection, potentially extracting sensitive database contents or modifying data.
- Remediation
- Update ImpressCMS to version 1.4.3 or later.
Template by ProjectDiscovery nuclei-templates (ritikchaddha), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2021-26599 in your dependencies?
O3 Security finds CVE-2021-26599 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.