CVE-2026-66398

9.4 CRITICAL 0.4% exploit odds Fix listed Code execution Web app

What it is

phpMyFAQ before v4.1.6 contains a remote code execution vulnerability in the configuration API that allows authenticated administrators with CONFIGURATION_EDIT and ATTACHMENT_ADD privileges to write arbitrary PHP files by manipulating the upgrade.lastDownloadedPackage setting. Attackers can upload a malicious ZIP file as an attachment, point the updater configuration to its stored path, and extract it into the application root to achieve code execution as the web server user.

At a glance

Exploitability: Can be exploited over the network with an admin-level account. High risk of data exposure, data tampering, service disruption.
Exploit odds: 0.4% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-07-27 16:18 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-10-24 13:10 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.4% in the next 30 days (EPSS).
Severity: 9.4 CRITICAL (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-07-27 16:18 UTC
Last modified: 2026-10-24 13:10 UTC
Exploit probability: 0.4% · EPSS, next 30 days
Weakness: CWE-494
Record status: Deferred

Attack profile CVSS 4.0 · 9.4

Attack vector: Network
Complexity: Low
Attack requirements: None
Privileges needed: High
User interaction: None
Confidentiality: High
Integrity: High
Availability: High

Raw vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-66398.md and follow it. Check whether this project is affected by CVE-2026-66398. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record