critical Known exploitedREV. 01

CVE-2017-9841PHPUnit — Code Execution via a Reachable Test Helper

A test helper shipped inside a widely used testing library runs whatever code arrives in a request body, and it is routinely left reachable inside deployed web roots.

YOUR NEXT MOVE

Upgrade to 4.8.28 or 5.6.3, and keep development dependencies out of anything served to the web.

Read the risk

THE VITAL STATS
CVSS score
9.8/ 10
CVSS v3.1
EPSS probability
100%
Likelihood of exploitation
Attack complexity
Low
Conditions needed to exploit
Known exploited
Yes — CISA KEV
CVE published
2017-06-27
Added to KEV
2022-02-15
Exploit published
Not recorded
Confidence
high
Kill chain
initial access
MITRE ATT&CK
T1190, T1059
Severity
critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attacker needsThe test helper reachable under the web root

Fixed inPHPUnit 4.8.28, PHPUnit 5.6.3

Behind the card

5 REFERENCES
Field-level provenanceTRACE THE SOURCES +

Which source supports each field, when it was retrieved, and who extracted it.

FieldsSourceRetrievedExtractorConfidence
cvss, exploitation.attack_complexity, exploitation.exploit_available, references, published_atnvd.nist.gov2026-08-07scrty-crds-pipeline/0.1high
exploitation.known_exploited, exploitation.kev_addedcisa.gov2026-08-07scrty-crds-pipeline/0.1high
epssapi.first.org2026-08-07scrty-crds-pipeline/0.1high
title, summary, severity, remediation, mitre_attack, kill_chain, recommended_action, confidence, tags, exploitation.prerequisitesnvd.nist.gov2026-08-07claude-codehigh

Printing history

THE RECORD
  1. r1Initial base card

First printing. This card has not been reprinted since publication.

crds:cve-2017-9841 · CRDS 0.1 · Issued 2026-08-07