Background exploitation KEV catalog
CVE-2026-34621

Adobe Acrobat and Reader Prototype Pollution Vulnerability

Acrobat Reader versions 24.001.30356, 26.001.21367 and earlier are affected by an Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') vulnerability that could result in arbitrary code execution in the…

CheckOps priority index
4.9/10 Patch within 7 days
Severity8.6
Probability0.7
Exploitation2/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 7.2% higher than 94.3% of CVEs
CVSS 3.1 8.6 AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:
Exploited for 204 days 13 Apr 2026
CISA due date 27 Apr 2026 for US federal agencies

Exploitation probability EPSS · FIRST

05010025 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 2 / 5

  • KEV catalog (CISA)13 Apr 2026
  • Exploited in EUVD (ENISA)13 Apr 2026
  • Used by ransomwareno
  • EPSS above 10 %7.2%
  • No account, over the networkno

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

Acrobat Reader versions 24.001.30356, 26.001.21367 and earlier are affected by an Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Affected products

Acrobat DCAcrobat Reader DCAcrobat 2024Acrobat and Reader
Affected versions
  • 0 ≤26.001.21367
  • 0 ≤24.001.30356
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

References

Other exploited vulnerabilities from the same vendor

  • CVE-2026-48356Adobe Commerce and Magento Unrestricted Upload of File with Dangerous Type Vulnerability
    7.5 · Rising fast
  • CVE-2026-71362Adobe Commerce and Magento Incorrect Authorization Vulnerability
    8.8 · Actively exploited
  • CVE-2026-75650Adobe Commerce and Magento Improper Neutralization of Special Elements Used in a Template Engine Vulnerability
    5.9 · Actively exploited
  • CVE-2026-48282Adobe ColdFusion Path Traversal Vulnerability
    7.7 · Actively exploited
  • CVE-2009-3459Adobe Acrobat and Reader Heap-Based Buffer Overflow Vulnerability
    8.5 · Actively exploited
  • CVE-2020-9715Adobe Acrobat Use-After-Free Vulnerability
    5.9 · Background exploitation

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities