CVE-2026-47926 Overview
CVE-2026-47926 is an out-of-bounds read vulnerability [CWE-125] affecting Adobe Acrobat Reader versions 24.001.30365, 26.001.21651, and earlier. The flaw allows an attacker to read memory outside the bounds of an allocated buffer, potentially disclosing sensitive process memory contents. Exploitation requires user interaction: a victim must open a malicious file crafted by the attacker. Successful exploitation does not impact file integrity or availability but can leak confidential data from the Reader process address space. Adobe published advisory APSB26-63 to address the issue.
Critical Impact
An attacker can disclose sensitive memory contents from the Acrobat Reader process when a victim opens a maliciously crafted PDF document.
Affected Products
- Adobe Acrobat Reader 24.001.30365 and earlier
- Adobe Acrobat Reader 26.001.21651 and earlier
- Adobe Acrobat (matching track versions per APSB26-63)
Discovery Timeline
- 2026-06-09 - CVE-2026-47926 published to the National Vulnerability Database (NVD)
- 2026-06-10 - Last updated in NVD database
Technical Details for CVE-2026-47926
Vulnerability Analysis
The issue is an out-of-bounds read in Adobe Acrobat Reader's file parsing logic. When the application processes a malformed PDF object, it reads beyond the boundaries of an allocated buffer. The returned bytes can include adjacent heap data such as pointers, object metadata, or fragments of previously processed documents.
The vulnerability impacts confidentiality only. It does not corrupt memory or terminate the process, which makes detection harder during routine use. The Common Weakness Enumeration (CWE) classification is [CWE-125] Out-of-Bounds Read. The Exploit Prediction Scoring System (EPSS) probability is 0.022% with a percentile of 6.419, indicating low observed exploitation likelihood at publication.
Root Cause
The root cause is missing or incorrect bounds validation when parsing a structure inside the PDF file format. The parser trusts a length or offset field from the document, then dereferences memory using that value without verifying it falls within the allocated region. Adobe's advisory APSB26-63 confirms an out-of-bounds read condition leading to memory disclosure.
Attack Vector
The attack is local and requires user interaction. An attacker delivers a crafted PDF through email, a download link, or a shared file repository. The victim opens the file in a vulnerable Acrobat Reader build, triggering the parser path that performs the out-of-bounds read. Sensitive bytes can then be exfiltrated through embedded JavaScript actions, form submissions, or rendered content that reflects the leaked data back to the attacker.
No verified public proof-of-concept code is available. Refer to the Adobe Security Advisory APSB26-63 for vendor technical details.
Detection Methods for CVE-2026-47926
Indicators of Compromise
- PDF files containing malformed objects, unusual stream lengths, or crafted cross-reference tables that trigger parser anomalies.
- Acrobat Reader processes initiating outbound network connections immediately after opening a document, suggesting data exfiltration via embedded actions.
- Acrobat Reader spawning child processes or accessing memory regions inconsistent with normal document rendering.
Detection Strategies
- Inspect PDF documents at the email and web gateway for structural anomalies using a PDF-aware parser.
- Track Acrobat Reader version inventory and flag endpoints running builds at or below 24.001.30365 and 26.001.21651.
- Correlate document-open events with subsequent network egress from AcroRd32.exe or Acrobat.exe.
Monitoring Recommendations
- Enable process and network telemetry from Acrobat Reader to a centralized data lake for retrospective hunting.
- Alert on PDFs delivered with embedded JavaScript or submitForm actions that contact external hosts.
- Monitor endpoint logs for Acrobat Reader crashes or repeated anomalous reads against the same file.
How to Mitigate CVE-2026-47926
Immediate Actions Required
- Apply the Adobe security update referenced in APSB26-63 to all Acrobat and Reader installations.
- Identify endpoints running Acrobat Reader 24.001.30365, 26.001.21651, or earlier and prioritize patching.
- Block inbound PDFs from untrusted senders at the email gateway until patches are deployed.
Patch Information
Adobe addressed CVE-2026-47926 in the updates published with Adobe Security Advisory APSB26-63. Administrators should update Acrobat Reader to the fixed builds listed in the advisory and verify through the Help menu or enterprise deployment tooling.
Workarounds
- Enable Protected View and Protected Mode in Acrobat Reader to constrain parser operations within a sandbox.
- Disable JavaScript execution in Acrobat Reader via Edit > Preferences > JavaScript to limit exfiltration paths.
- Restrict PDF rendering to a hardened viewer or browser-based renderer for documents from untrusted sources until patching completes.
# Disable Acrobat JavaScript via Windows registry (enterprise rollout)
reg add "HKLM\SOFTWARE\Policies\Adobe\Acrobat Reader\DC\FeatureLockDown" /v bDisableJavaScript /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.
