CVE-2019-18888 — http-foundation
HIGHCVE-2019-18888 is a high-severity (CVSS 7.5) CWE-88 vulnerability in symfony/http-foundation. A fix is available for symfony/http-foundation — see the affected versions and patch details below.
Argument injection in a MimeTypeGuesser in Symfony
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2019-18888 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 384,189 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
symfony/http-foundation🐘symfony/http-foundation🐘symfony/http-foundation🐘symfony/http-foundation🐘symfony/mime🐘symfony/symfony🐘symfony/symfony🐘symfony/symfony+1 moreReal-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
An issue was discovered in Symfony 2.8.0 through 2.8.50, 3.4.0 through 3.4.34, 4.2.0 through 4.2.11, and 4.3.0 through 4.3.7. If an application passes unvalidated user input as the file for which MIME type validation should occur, then arbitrary arguments are passed to the underlying file command. This is related to symfony/http-foundation (and symfony/mime in 4.3.x).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | symfony/http-foundation | ≥ 2.0.0&&< 2.8.52 | 2.8.52composer require symfony/http-foundation:^2.8.52 |
| 🐘Packagist | symfony/http-foundation | ≥ 3.0.0&&< 3.4.35 | 3.4.35composer require symfony/http-foundation:^3.4.35 |
| 🐘Packagist | symfony/http-foundation | ≥ 4.0.0&&< 4.2.12 | 4.2.12composer require symfony/http-foundation:^4.2.12 |
| 🐘Packagist | symfony/http-foundation | ≥ 4.3.0&&< 4.3.8 | 4.3.8composer require symfony/http-foundation:^4.3.8 |
| 🐘Packagist | symfony/mime | ≥ 4.3.0&&< 4.3.8 | 4.3.8composer require symfony/mime:^4.3.8 |
| 🐘Packagist | symfony/symfony | ≥ 2.0.0&&< 2.8.52 | 2.8.52composer require symfony/symfony:^2.8.52 |
Affected Products
fedorafedoraprojectsymfonysensiolabsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symfony/http-foundation, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update symfony/http-foundation to 2.8.52 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-18888 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.
Frequently Asked Questions
Is CVE-2019-18888 in your dependencies?
Find it across Packagist, including transitive dependencies.