CVE-2026-46420

MEDIUMPre-NVD 5.65.6—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 1.1%, top 36% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.6EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 5.6Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

setup-php is a GitHub action to set up PHP with extensions, php.ini configuration, coverage drivers, and tools. From 2.25.0 prior to 2.37.1, shivammathur/setup-php resolves the PHP version from repository-controlled files such as .php-version, composer.lock through platform-overrides.php, and composer.json through config.platform.php, and insufficiently constrains those values before incorporating them into generated shell or PowerShell setup scripts, allowing command injection on a GitHub Actions runner when workflows such as pull_request_target check out attacker-controlled contents before invoking setup-php. This issue is fixed in version 2.37.1.

CVSS v3
5.6
EG Score
5.6(medium)
EG Risk
26(Track)
EG Risk 26/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity56% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
64%
KEV
Not listed

Published

May 20, 2026

Last Modified

July 23, 2026

Advisory Details (3)

Auto-updated Jul 17, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

Command Injection in Repository-Derived PHP Version Resolution · Advisory · shivammathur/setup-php · GitHub

https://github.com/shivammathur/setup-php/security/advisories/GHSA-pqwm-q9pv-ph8r
github_release Patch Available

2.37.1

Patch available: shivammathur/setup-php 2.37.1

https://github.com/shivammathur/setup-php/releases/tag/2.37.1
github_commit Patch Available

commit eeef37e059fb (shivammathur/setup-php)

Patch available: shivammathur/setup-php 2.37.1 (contains commit eeef37e059fb)

https://github.com/shivammathur/setup-php/commit/eeef37e059fb5368a5bc8ed8ce45ff54bd39b80b

Vendor Advisories for CVE-2026-46420(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 12× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-28 15:36 UTCEPSS rescore
  2. 2026-07-27 14:13 UTCEPSS rescore
  3. 2026-07-26 08:14 UTCEG score recompute
  4. 2026-07-25 14:18 UTCEPSS rescore
  5. 2026-07-24 14:17 UTCEPSS rescore
  6. 2026-07-23 14:18 UTCEPSS rescore
  7. 2026-07-23 03:17 UTCEG score recompute
  8. 2026-07-22 14:08 UTCEPSS rescore
  9. 2026-07-21 15:24 UTCEPSS rescore
  10. 2026-07-20 17:08 UTCEPSS rescore
  11. 2026-07-19 14:31 UTCEPSS rescore
  12. 2026-07-19 02:29 UTCEPSS rescore
  13. 2026-06-14 23:18 UTCEPSS rescore
  14. 2026-06-13 23:00 UTCEPSS rescore
  15. 2026-06-12 23:12 UTCEPSS rescore
  16. 2026-05-24 06:12 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-46420?
CVE-2026-46420 is a medium vulnerability published on May 20, 2026. setup-php is a GitHub action to set up PHP with extensions, php.ini configuration, coverage drivers, and tools. From 2.25.0 prior to 2.37.1, shivammathur/setup-php resolves the PHP version from repository-controlled files such as .php-version, composer.lock through platform-overrides.php, and…
When was CVE-2026-46420 disclosed?
CVE-2026-46420 was first published in the National Vulnerability Database on May 20, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-46420 actively exploited?
CVE-2026-46420 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 36.4% of all scored CVEs.
What is the CVSS score of CVE-2026-46420?
CVE-2026-46420 has a CVSS v3 base score of 5.6 (NVD).
How do I remediate CVE-2026-46420?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-46420, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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