Hazard

Is CVE-2026-34621 being exploited?

Confirmed exploited in the wild

CISA has evidence of active exploitation. This is not theoretical risk — someone has already used it against someone.

Adobe Acrobat and Reader Prototype Pollution Vulnerability

Adobe · Acrobat and Reader

CVSS 8.6 EPSS 7% no public exploit indexed Fix deadline passed 27 April 2026

What it is

Adobe Acrobat and Reader contain a prototype pollution vulnerability that allows for arbitrary code execution.

Why we say that

  • CISA's federal remediation deadline (2026-04-27) has passed
  • 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, follow applicable BOD 22-01 guidance for cloud services, 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 →