CVE-2026-47911 Overview
CVE-2026-47911 is an out-of-bounds write vulnerability [CWE-787] affecting Adobe Acrobat Reader versions 24.001.30365, 26.001.21651, and earlier. Successful exploitation allows arbitrary code execution in the context of the current user. The flaw requires user interaction — a victim must open a malicious PDF file crafted by an attacker.
Adobe addressed the issue in security advisory APSB26-63. The vulnerability carries a CVSS v3.1 base score of 7.8, reflecting local attack vector with high impact to confidentiality, integrity, and availability. No public proof-of-concept exploit or in-the-wild exploitation has been reported at this time.
Critical Impact
Attackers can achieve arbitrary code execution under the current user's privileges by tricking a victim into opening a malicious PDF document.
Affected Products
- Adobe Acrobat Reader version 24.001.30365 and earlier
- Adobe Acrobat Reader version 26.001.21651 and earlier
- Adobe Acrobat (corresponding tracks per APSB26-63)
Discovery Timeline
- 2026-06-09 - CVE-2026-47911 published to NVD
- 2026-06-10 - Last updated in NVD database
Technical Details for CVE-2026-47911
Vulnerability Analysis
The vulnerability is an out-of-bounds write condition within Adobe Acrobat Reader's PDF parsing logic. Out-of-bounds writes occur when a program writes data past the boundaries of an allocated memory buffer. This corrupts adjacent memory structures such as heap metadata, function pointers, or object virtual tables.
An attacker who controls the data written beyond the buffer can manipulate program control flow. In Acrobat Reader, this typically results in arbitrary code execution under the rendering process. The process inherits the privileges of the current user, allowing the attacker to access files, install programs, or pivot within the environment.
The vulnerability requires user interaction. The victim must open a malicious PDF, either directly from disk or through a browser plugin that invokes Acrobat Reader. Standard phishing delivery vectors apply.
Root Cause
The root cause is improper validation of size or index parameters during PDF object parsing. When the renderer processes a crafted PDF structure, it writes attacker-controlled data outside the bounds of an allocated buffer, corrupting memory in the renderer process.
Attack Vector
The attack vector is local and requires user interaction. An attacker delivers a crafted PDF through email attachments, malicious downloads, or compromised websites. Opening the file in a vulnerable Acrobat Reader version triggers the memory corruption and enables code execution.
No public exploitation code or proof-of-concept has been released. Refer to the Adobe Security Advisory APSB26-63 for vendor technical details.
Detection Methods for CVE-2026-47911
Indicators of Compromise
- Unexpected child processes spawned by AcroRd32.exe or Acrobat.exe, such as cmd.exe, powershell.exe, or wscript.exe
- Crash events or Windows Error Reporting entries naming Acrobat Reader modules with access violation exceptions
- PDF files originating from untrusted email senders or web downloads, especially with embedded JavaScript or malformed object streams
- Outbound network connections initiated by the Acrobat Reader process to previously unseen domains
Detection Strategies
- Monitor process lineage for Acrobat Reader spawning interpreters, shells, or LOLBins commonly used in post-exploitation
- Inspect PDFs at the email gateway for suspicious object structures, embedded JavaScript, and known malicious patterns
- Apply YARA rules targeting malformed PDF cross-reference tables and oversized object streams associated with out-of-bounds write triggers
- Correlate Acrobat Reader crash telemetry with subsequent suspicious file or registry modifications on the same host
Monitoring Recommendations
- Enable command-line and process creation auditing on endpoints running Acrobat Reader
- Forward Acrobat Reader crash logs to a centralized SIEM for review
- Track installed Acrobat Reader versions across the fleet and flag hosts running vulnerable builds
How to Mitigate CVE-2026-47911
Immediate Actions Required
- Update Adobe Acrobat Reader to the fixed versions identified in Adobe Security Advisory APSB26-63
- Inventory all endpoints running vulnerable Acrobat Reader builds 24.001.30365, 26.001.21651, and earlier
- Restrict execution of PDFs from untrusted sources via email filtering and web content controls
- Enable Protected View and Protected Mode in Acrobat Reader for all users
Patch Information
Adobe released fixed builds as part of advisory APSB26-63 on June 9, 2026. Apply the updates referenced in the Adobe Security Advisory APSB26-63. Enterprise administrators should deploy patches through their standard software distribution channels and verify version compliance afterward.
Workarounds
- Enable Protected View for files originating from the Internet and potentially unsafe locations
- Disable JavaScript execution within Acrobat Reader through the Preferences interface or Group Policy
- Block PDF attachments from external senders at the email gateway pending patch deployment
- Use application allowlisting to prevent Acrobat Reader from spawning command interpreters
# Group Policy registry settings to harden Acrobat Reader
# Enable Protected View for all files
reg add "HKCU\Software\Adobe\Acrobat Reader\DC\TrustManager" /v iProtectedView /t REG_DWORD /d 2 /f
# Disable JavaScript execution
reg add "HKCU\Software\Adobe\Acrobat Reader\DC\JSPrefs" /v bEnableJS /t REG_DWORD /d 0 /f
# Enable Protected Mode
reg add "HKCU\Software\Adobe\Acrobat Reader\DC\Privileged" /v bProtectedMode /t REG_DWORD /d 1 /f
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
