VulnerabilityAnalyzed

CVE-2026-34621

Adobe Acrobat and Reader Prototype Pollution Vulnerability

KEVHIGH 8.6EPSS 7.09%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 27 April 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

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.

CVSS 3.1: 8.6 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS: 7.09% probability · 94th percentile
CISA KEV: Listed 13 April 2026 · due 27 April 2026
Weakness: CWE-1321
Affected: adobe/acrobat dc · adobe/acrobat reader dc · adobe/acrobat
Source: psirt@adobe.com

CISA notes

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://helpx.adobe.com/security/products/acrobat/apsb26-43.html ; https://nvd.nist.gov/vuln/detail/CVE-2026-34621

References

https://helpx.adobe.com/security/products/acrobat/apsb26-43.htmlVendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-34621US Government Resource

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.