How severe is CVE-2017-9841?

CVE-2017-9841 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2017-9841?

CVE-2017-9841 affects the following packages: phpunit/phpunit (Packagist), phpunit/phpunit (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2017-9841?

Update phpunit/phpunit to version 4.8.28 or later. Run your dependency manager's update command and verify no transitive dependencies pin the vulnerable version. Use O3 Security's SCA scanner to confirm the fix is applied across your entire dependency tree.

Is CVE-2017-9841 actively exploited in the wild?

Yes. There are 25 known exploit references for CVE-2017-9841, including 1 documented proof-of-concept exploit on Exploit-DB and 14 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2017-9841?

CVE-2017-9841 has an EPSS (Exploit Prediction Scoring System) score of 94.2%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2017-9841 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2017-9841 (PHPUnit Command Injection Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-02-15. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-08-15. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2017-9841?

CVE-2017-9841 is classified as Code Injection (CWE-94). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Is there exploit tooling available for CVE-2017-9841?

A Nuclei detection template exists for CVE-2017-9841, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2017-9841 published, and has it been updated?

CVE-2017-9841 was published on June 27, 2017 and was last updated on April 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2022-02-15 — agencies required to remediate by 2022-08-15

🐘 Packagist

CVE-2017-9841

CRITICAL

Code Injection in PHPUnit

Also known asGHSA-r7c9-c69m-rph8

Published

Jun 27, 2017

Updated

Apr 16, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

25 known

EPSS Exploitation Probability

via FIRST.org ↗

94.2%probability of exploitation in next 30 days

Very High Risk100th percentile0.00%

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.

Blast Radius

2 pkgs affected

🐘phpunit/phpunit🐘phpunit/phpunit

Real-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

Util/PHP/eval-stdin.php in PHPUnit before 4.8.28 and 5.x before 5.6.3 allows remote attackers to execute arbitrary PHP code via HTTP POST data beginning with a "<?php " substring, as demonstrated by an attack on a site with an exposed /vendor folder, i.e., external access to the /vendor/phpunit/phpunit/src/Util/PHP/eval-stdin.php URI.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`phpunit/phpunit`	≥ 4.8.19&&< 4.8.28	4.8.28
🐘Packagist	`phpunit/phpunit`	≥ 5.0.10&&< 5.6.3	5.6.3

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-50702webappsphp

PHP Unit 4.8.28 - Remote Code Execution (RCE) (Unauthenticated)

by souzo · Feb 2, 2022

Exploit-DB Source

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2017-9841 in your stack?

O3 detects CVE-2017-9841 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my stack How O3 SCA works

CVSS Score

9.8/10

CVSS v3 base score

Vector breakdown

AV:Attack Vector

Network

AC:Attack Complexity

Low

PR:Privileges Required

None

UI:User Interaction