CVE-2026-47959: Adobe Acrobat Reader Stack Buffer Overflow RCE Vulnerability

Technical summary

CVE-2026-47959 is a stack-based buffer overflow vulnerability (CWE-121) in Adobe Acrobat Reader that arises from improper input validation when processing malicious file content. The vulnerability allows unauthenticated, local code execution in the context of the current user without special privileges. The CVSS 3.1 score of 7.8 reflects high confidentiality, integrity, and availability impact with low attack complexity and no privilege escalation required—though user interaction (opening a malicious file) is necessary. The issue affects Acrobat Reader on both Windows and macOS platforms.

Business impact

This vulnerability poses a meaningful risk to any organization where employees regularly handle PDF documents or use Acrobat Reader for document viewing and annotation. Successful exploitation could lead to unauthorized access to sensitive files, lateral movement within the network, or installation of malware—all initiated through a seemingly innocent file open action. Organizations relying on Acrobat for secure document workflows should treat this as a priority remediation item to prevent potential data exfiltration or system compromise.

Affected systems

Adobe Acrobat Reader versions 24.001.30365 and 26.001.21651 or earlier on Windows and macOS are affected. Organizations should verify their current Acrobat Reader deployment versions and assess the scope of exposure across their user base. Both current and legacy deployment tracks may require attention depending on your organization's update practices.

Exploitability

Exploitation requires user interaction—specifically, the victim must open a malicious file crafted to trigger the buffer overflow. No authentication or special user privileges are needed on the target system. The attack vector is local, meaning the malicious file must reach the user's system (via email, web download, file share, etc.), and the user must be persuaded to open it. No public exploit code or evidence of active exploitation in the wild has been documented at the time this vulnerability was published, though organizations should assume adversaries will develop and deploy working exploits given the high severity and user-interaction requirement.

Remediation

Adobe will release patched versions of Acrobat Reader to address this vulnerability. Organizations should monitor Adobe's security advisories for specific patch version numbers and apply updates as soon as they become available and have been validated in your environment. Until patches are deployed, consider implementing user awareness training to recognize and avoid opening suspicious files from untrusted sources, and enforce file type restrictions where feasible.

Patch guidance

Check Adobe's official security update portal for the latest Acrobat Reader patches addressing CVE-2026-47959. Before deploying to production, validate patch compatibility with your organization's document workflows, integrations, and hardware. Stagger rollout to detect any unforeseen issues before full deployment. Verify against the vendor advisory that the specific patch version resolves this vulnerability, as Adobe may release updates for multiple Acrobat Reader versions concurrently. Test patches in a non-production environment first, particularly if Acrobat is mission-critical to your document handling processes.

Detection guidance

Monitor for unusual Acrobat Reader process behavior such as unexpected child process spawning, outbound network connections, or suspicious file system activity immediately following file open actions. Implement file integrity monitoring and behavioral analysis on endpoints where Acrobat Reader is heavily used. Consider deploying anti-exploit protections that can detect stack manipulation techniques. Web and email filtering can help reduce malicious file delivery by blocking suspicious PDF attachments or detecting known malicious file signatures. Endpoint detection and response (EDR) solutions with buffer overflow detection capabilities are valuable for identifying exploitation attempts.

Why prioritize this

This vulnerability earns high prioritization due to its combination of high CVSS severity (7.8), widespread user base exposure, and low barrier to initial compromise—user interaction is common in document-centric workflows. While not yet listed in the CISA KEV catalog, the exploitability pathway and high-impact code execution potential make it a significant risk. Acrobat Reader's ubiquity in business environments means that patching this issue defensively will reduce risk across many organizations in parallel.

Risk score, explained

The CVSS 3.1 score of 7.8 (HIGH) reflects: (1) high confidentiality impact—attackers can read memory and bypass protections; (2) high integrity impact—code execution allows modification of system and user data; (3) high availability impact—malicious code can crash the application or disable systems; (4) local attack vector with no privilege escalation; (5) low attack complexity—a single crafted file can trigger the flaw; (6) user interaction requirement, which reduces but does not eliminate risk. The score appropriately captures the severity for a local code execution vulnerability in widely-deployed software.

Frequently asked questions