CVE-2026-47955 Overview
CVE-2026-47955 is a Use After Free vulnerability [CWE-416] in Adobe Acrobat Reader. The flaw affects Acrobat Reader versions 24.001.30365, 26.001.21651, and earlier releases. Successful exploitation allows attackers to achieve arbitrary code execution in the context of the current user. Exploitation requires user interaction. A victim must open a crafted malicious PDF file to trigger the vulnerability. Adobe addressed this issue in security advisory APSB26-63.
Critical Impact
Attackers can execute arbitrary code on a victim's system after the user opens a malicious PDF, leading to full compromise under the user's privileges.
Affected Products
- Adobe Acrobat Reader version 24.001.30365
- Adobe Acrobat Reader version 26.001.21651
- Adobe Acrobat Reader earlier versions in these branches
Discovery Timeline
- 2026-06-09 - CVE-2026-47955 published to NVD
- 2026-06-10 - Last updated in NVD database
Technical Details for CVE-2026-47955
Vulnerability Analysis
The vulnerability is a Use After Free condition in Adobe Acrobat Reader's document processing logic. Use After Free flaws occur when a program continues to reference memory after it has been freed. An attacker who controls the contents of the reclaimed allocation can hijack control flow when the dangling pointer is dereferenced.
The attack vector is local and requires user interaction. The victim must open a malicious PDF file delivered through phishing, drive-by download, or shared file storage. Code executes with the privileges of the user running Acrobat Reader. On systems where users hold administrative rights, attackers gain full host control.
The Common Weakness Enumeration mapping is [CWE-416]. No public proof-of-concept exploit is available at the time of publication, and the issue is not listed in the CISA Known Exploited Vulnerabilities catalog.
Root Cause
The root cause is improper memory management within Acrobat Reader's PDF parsing or rendering routines. An object is freed while a pointer to it remains accessible. When the dangling pointer is later dereferenced, the freed memory may already be reallocated with attacker-controlled data, enabling arbitrary code execution.
Attack Vector
The attack chain begins with delivery of a malicious PDF document. When opened in a vulnerable Acrobat Reader build, the embedded structures trigger the Use After Free condition. Attackers typically combine the primitive with heap grooming and ASLR bypass techniques to achieve reliable arbitrary code execution.
No verified exploit code is publicly available. Refer to the Adobe Acrobat Security Advisory for vendor technical details.
Detection Methods for CVE-2026-47955
Indicators of Compromise
- Unexpected crashes of AcroRd32.exe or Acrobat.exe when opening PDF attachments
- PDF files originating from untrusted email senders or unfamiliar external links
- Child processes such as cmd.exe, powershell.exe, or rundll32.exe spawned by Acrobat Reader
- Outbound network connections initiated by Acrobat Reader to unknown infrastructure
Detection Strategies
- Monitor process lineage to flag any non-standard child process spawned by Acrobat Reader
- Inspect PDF documents for embedded JavaScript, suspicious object streams, and malformed cross-reference tables
- Correlate Acrobat Reader crash events with subsequent process creation or file write activity
- Apply behavioral analytics to detect memory corruption indicators such as exception handler abuse
Monitoring Recommendations
- Enable command-line auditing and PowerShell script block logging on endpoints running Acrobat Reader
- Track installed Acrobat Reader versions across the fleet to identify unpatched hosts
- Forward endpoint telemetry to a centralized data lake for retrospective hunting
- Alert on PDF files sourced from email arriving at high-value user inboxes
How to Mitigate CVE-2026-47955
Immediate Actions Required
- Apply Adobe's security update referenced in advisory APSB26-63 to all Acrobat Reader installations
- Identify and prioritize patching on endpoints used by high-risk users such as executives and finance staff
- Block inbound email attachments containing PDFs from untrusted external senders pending patch deployment
- Restrict administrative privileges on user workstations to limit blast radius of successful exploitation
Patch Information
Adobe published fixed builds in security advisory APSB26-63. Administrators should upgrade Acrobat Reader beyond versions 24.001.30365 and 26.001.21651. Consult the Adobe Acrobat Security Advisory for the complete list of patched releases and download links.
Workarounds
- Enable Protected View and Protected Mode in Acrobat Reader to sandbox untrusted PDF rendering
- Disable JavaScript in Acrobat Reader through Edit > Preferences > JavaScript to reduce attack surface
- Configure email gateways to detonate PDF attachments in a sandbox before delivery
- Use group policy to enforce the latest Acrobat Reader version across managed endpoints
# Configuration example - disable JavaScript in Acrobat Reader via Windows registry
reg add "HKLM\SOFTWARE\Policies\Adobe\Acrobat Reader\DC\FeatureLockDown" /v bDisableJavaScript /t REG_DWORD /d 1 /f
# Enforce Protected View for all files
reg add "HKLM\SOFTWARE\Policies\Adobe\Acrobat Reader\DC\FeatureLockDown" /v iProtectedView /t REG_DWORD /d 2 /f
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
