Hazard

Is CVE-2023-36845 being exploited?

Weaponised and widely attempted

Reliable public exploit code exists, or mass exploitation attempts are probable. Patch inside days, not weeks.

Juniper Junos OS EX Series and SRX Series PHP External Variable Modification Vulnerability

Juniper · Junos OS

CVSS 9.8 EPSS 94% no public exploit indexed Fix deadline passed 17 November 2023

What it is

Juniper Junos OS on EX Series and SRX Series contains a PHP external variable modification vulnerability that allows an unauthenticated, network-based attacker to control an important environment variable. Using a crafted request, which sets the variable PHPRC, an attacker is able to modify the PHP execution environment allowing the injection und execution of code.

Why we say that

  • EPSS puts exploitation in the next 30 days at 94%
  • CISA's federal remediation deadline (2023-11-17) has passed
  • CVSS 9.8 critical
  • Listed in the CISA Known Exploited Vulnerabilities catalogue

Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.

What to do

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

What it costs when this goes wrong

This is where UK enforcement meets the vulnerability record. Where an unfixed vulnerability leads to a breach, the ICO treats it as a security failure under UK GDPR. Recent cases:

All UK cases caused by unpatched software →