⚠ Actively exploited
Added to CISA KEV on 2026-04-13. Federal agencies required to patch by 2026-04-27. Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable..

CVE-2026-34621

Severity
8.6HIGH
EPSS
0.0%
top 88.63%
CISA KEV
KEV
Added 2026-04-13
Due 2026-04-27
Exploit
No known exploits
Affected products
Timeline
PublishedApr 11
KEV addedApr 13
KEV dueApr 27
CISA Required Action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

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 vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:HExploitability: 2.8 | Impact: 6.0

Affected Packages1 packages

CVEListV5adobe/acrobat_reader26.001.21367

🔴Vulnerability Details

4
CVEList
Acrobat Reader | Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (CWE-1321)2026-04-11
GHSA
GHSA-vcqh-932g-m3qj: Acrobat Reader versions 242026-04-11
VulDB
Adobe Acrobat Reader up to 24.001.30356/26.001.21367 File prototype pollution (apsb26-43)2026-04-11
VulnCheck
Adobe Acrobat and Reader Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')2026

📋Vendor Advisories

1
CISA
Adobe Acrobat and Reader Prototype Pollution Vulnerability2026-04-13

🕵️Threat Intelligence

2
Bleepingcomputer
Adobe rolls out emergency fix for Acrobat, Reader zero-day flaw2026-04-13
Hackernews
Adobe Patches Actively Exploited Acrobat Reader Flaw CVE-2026-346212026-04-12