Exploited· due 2026-04-278.6highHigh
CVE-2026-34621
Adobe Acrobat Dc
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.
Exploitation status
- CISA has confirmed this is being exploited in the wild. That is an observation of real attacks, not a prediction.
- US federal civilian agencies are required to remediate it by 2026-04-27. That deadline does not bind private companies, but it is a reasonable benchmark for how urgently CISA views it.
- A vendor advisory or patch reference has been published.
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.
CISA’s wording, unedited.
What the metrics mean
- It is requires local access to the machine.
- For an attacker who can reach it, no special conditions are needed to exploit it.
- To exploit it, no account is needed.
- Beyond that, someone has to be persuaded to take an action first.
Scoring
- CVSS
- 8.6 (v3.1)
- Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H- Weakness
- CWE-1321
- Assigned by
- psirt@adobe.com
Dates
- Published
- 2026-04-11
- Last modified
- 2026-08-28
- Added to KEV
- 2026-04-13
- Remediation due
- 2026-04-27
- Sources
- CISA KEV, NVD
Affected products
- Adobe Acrobat Dc- 26.001.21411
- Adobe Acrobat Reader Dc- 26.001.21411
- Apple Macosall versions
- Microsoft Windowsall versions
- Adobe Acrobat24.0.0 - 24.001.30362, 24.0.0 - 24.001.30360
As listed in the NVD configuration data. Not a statement about your estate.