CVE-2026-47952: Acrobat Reader Buffer Overflow Vulnerability

CVE-2026-47952 Overview

CVE-2026-47952 is a heap-based buffer overflow vulnerability [CWE-122] affecting Adobe Acrobat Reader versions 24.001.30365, 26.001.21651, and earlier. An attacker can achieve arbitrary code execution in the context of the current user. Exploitation requires user interaction, where the victim must open a crafted malicious file. The flaw resides in the document parsing path that handles malformed object structures within PDF files. Adobe has published a security bulletin addressing the issue.

Critical Impact
Arbitrary code execution in the current user context after a victim opens a malicious PDF document.

Affected Products

Adobe Acrobat Reader 24.001.30365 and earlier
Adobe Acrobat Reader 26.001.21651 and earlier
Adobe Acrobat (corresponding versions per Adobe advisory APSB26-63)

Discovery Timeline

2026-06-09 - CVE-2026-47952 published to NVD
2026-06-10 - Last updated in NVD database

Technical Details for CVE-2026-47952

Vulnerability Analysis

The vulnerability is a heap-based buffer overflow within Acrobat Reader's document parsing logic. Acrobat Reader allocates heap memory based on size fields embedded in a PDF object, then copies attacker-controlled data into that allocation. When the size accounting is incorrect, the copy operation writes past the end of the heap buffer. The corrupted heap metadata or adjacent object pointers can be leveraged to redirect control flow. Successful exploitation yields code execution with the privileges of the user who opened the document.

Root Cause

The root cause is improper validation of length or count fields used during heap allocation and subsequent memory copy operations. The mismatch between allocated buffer size and the data written produces an out-of-bounds write on the heap, classified as [CWE-122]. Adobe's advisory APSB26-63 attributes the issue to flawed bounds checking within the document parser.

Attack Vector

The attack vector is local and requires user interaction. An attacker delivers a crafted PDF through phishing email, web download, or a shared file location. When the victim opens the file in a vulnerable Acrobat Reader build, the malformed object triggers the overflow. No elevated privileges are required from the attacker prior to exploitation. The vulnerability does not provide network-based remote execution without user action.

No verified public proof-of-concept code is available. Refer to the Adobe Acrobat Security Advisory APSB26-63 for vendor-supplied technical context.

Detection Methods for CVE-2026-47952

Indicators of Compromise

Acrobat Reader processes (AcroRd32.exe, Acrobat.exe) spawning unexpected child processes such as cmd.exe, powershell.exe, or rundll32.exe.
Crash dumps or Windows Error Reporting entries referencing heap corruption in Acrobat Reader modules.
Inbound PDF attachments from untrusted senders containing malformed object streams or oversized length descriptors.

Detection Strategies

Monitor parent-child process relationships where Acrobat Reader launches scripting interpreters or shell binaries.
Inspect PDF files at the email gateway for malformed object trees, suspicious JavaScript, and abnormal stream length fields.
Apply YARA rules targeting known exploit patterns for heap overflows in Acrobat Reader PDF parsing.

Monitoring Recommendations

Enable command-line auditing and Sysmon Event ID 1 to capture process creation under Acrobat Reader.
Forward endpoint telemetry to a centralized analytics platform to correlate document-open events with subsequent suspicious activity.
Track Acrobat Reader version inventory across endpoints to identify unpatched hosts.

How to Mitigate CVE-2026-47952

Immediate Actions Required

Update Adobe Acrobat and Acrobat Reader to the fixed versions listed in Adobe advisory APSB26-63.
Restrict opening of PDF files from untrusted sources via email filtering and web proxy controls.
Enable Protected View and Protected Mode in Acrobat Reader to sandbox document rendering.

Patch Information

Adobe addresses CVE-2026-47952 in the security update referenced by Adobe Acrobat Security Advisory APSB26-63. Administrators should deploy the patched builds across all Windows and macOS endpoints running affected versions.

Workarounds

Configure Acrobat Reader to open PDFs in Protected View for all files originating outside trusted locations.
Disable JavaScript execution within Acrobat Reader through the Preferences interface or group policy.
Block inbound PDF attachments from external senders at the email gateway until patching completes.

bash

# Configuration example: disable Acrobat JavaScript via Windows registry
reg add "HKCU\Software\Adobe\Acrobat Reader\DC\JSPrefs" /v bEnableJS /t REG_DWORD /d 0 /f

# Enforce Protected View for all files
reg add "HKCU\Software\Adobe\Acrobat Reader\DC\TrustManager" /v iProtectedView /t REG_DWORD /d 2 /f