Adobe Acrobat Reader up to 24.001.30356/26.001.21367 File prototype pollution

Summaryinfo

A vulnerability was found in Adobe Acrobat Reader up to 24.001.30356/26.001.21367 and classified as critical. Affected by this issue is some unknown functionality of the component File Handler. Executing a manipulation can lead to prototype pollution. This vulnerability is tracked as CVE-2026-34621. The attack can be launched remotely. Moreover, an exploit is present. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Adobe Acrobat Reader up to 24.001.30356/26.001.21367 and classified as critical. This vulnerability affects an unknown code of the component File Handler. The manipulation with an unknown input leads to a prototype pollution vulnerability. The CWE definition for the vulnerability is CWE-1321. The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at helpx.adobe.com. This vulnerability was named CVE-2026-34621 since 03/30/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. Technical details are unknown but an exploit is available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 05/13/2026). This vulnerability is assigned to T1059 by the MITRE ATT&CK project.

It is declared as attacked. The vulnerability scanner Nessus provides a plugin with the ID 306009 (Adobe Reader < 26.001.21411 Vulnerability (APSB26-43) (macOS)), which helps to determine the existence of the flaw in a target environment. This issue was added on 04/13/2026 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 04/27/2026:

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

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at Zero-Day.cz (1089), Tenable (306009), EUVD (EUVD-2026-21675) and CERT Bund (WID-SEC-2026-1047). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Adobe Acrobat Reader
• Adobe Acrobat DC
• Adobe Acrobat Reader DC
• Adobe Acrobat

Productinfo

Type

• Document Reader Software

Vendor

• Adobe

Name

• Acrobat Reader

Version

• 24.001.30356
• 26.001.21367

License

• free

Website

• Vendor: https://www.adobe.com/

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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