CVE-2026-47918: Acrobat Reader Use-After-Free Remote Code Execution Vulnerability

Technical summary

CVE-2026-47918 is a use-after-free vulnerability (CWE-416) in Adobe Acrobat Reader that permits remote code execution in the security context of the current user. The flaw arises from improper memory management—specifically, the application attempts to access memory that has already been freed, allowing an attacker to manipulate that freed memory region to execute arbitrary instructions. Exploitation requires user interaction; the victim must open a crafted malicious file. The CVSS v3.1 score is 7.8 (HIGH), reflecting high impact across confidentiality, integrity, and availability with local attack vector and no privilege escalation required.

Business impact

Successful exploitation enables complete compromise of user data and system integrity on affected workstations. Attackers can steal sensitive documents, install persistent malware, or pivot to internal networks. Organizations relying on Acrobat Reader for document handling—particularly those processing untrusted external PDFs—face elevated risk. The user-interaction requirement means phishing campaigns distributing malicious documents are a realistic attack vector. Unpatched systems remain vulnerable to opportunistic attacks.

Affected systems

Adobe Acrobat Reader DC and Acrobat DC are affected on both Windows and macOS platforms. Specifically, versions 24.001.30365, 26.001.21651, and all earlier versions carry the vulnerability. Verify your installed version and platform against Adobe's official advisory to confirm exposure.

Exploitability

This vulnerability requires user interaction—a victim must open a malicious file. No remote, unauthenticated exploitation is possible without social engineering or drive-by delivery. The attacker typically embeds malicious code within a specially crafted PDF or document that, when opened in vulnerable Acrobat Reader versions, triggers the use-after-free condition. The CVSS vector reflects that no elevated privileges are needed pre-exploitation, and once triggered, the attacker gains full code execution capabilities of the current user. The vulnerability has not been added to CISA's Known Exploited Vulnerabilities catalog as of the current data, though active exploitation cannot be ruled out.

Remediation

Update Adobe Acrobat Reader to a patched version released on or after June 17, 2026. Adobe typically releases updates through their regular patch cycles; consult the official Adobe security advisory for specific version numbers to upgrade to. Implement application whitelisting or disable JavaScript execution in Acrobat Reader if business processes permit. Additionally, educate users to be cautious when opening unsolicited PDF attachments or files from untrusted sources.

Patch guidance

Apply Adobe's official security updates for Acrobat Reader as soon as practicable. Updates should be available through Adobe's automatic update mechanism (Enable Updates in Acrobat preferences) or manual download from adobe.com/security. Test patches in a controlled environment before widespread deployment to ensure compatibility with workflows and integrations. Verify the installed version post-patch against the advisory to confirm successful remediation.

Detection guidance

Monitor for suspicious Acrobat Reader process behavior, including unexpected child process spawning, network connections from the application, or registry modifications. Log file opens of unusual PDF files or those from unexpected sources. Endpoint Detection and Response (EDR) tools should flag use-after-free exploitation attempts if they include memory corruption signatures. Review email gateway logs for PDF attachments from external senders, particularly those with obfuscated or suspicious content. Correlate Acrobat Reader crashes or unresponsive processes with timeline of document opens.

Why prioritize this

This vulnerability merits high priority due to its high CVSS score (7.8), full code execution impact, and prevalence of Acrobat Reader across enterprises. While user interaction is required, phishing and social engineering remain effective delivery mechanisms. The broad Windows and macOS support means most organizations have exposed systems. Rapid patching reduces the attack surface before adversaries shift to widespread exploitation campaigns.

Risk score, explained

The CVSS 3.1 score of 7.8 (HIGH) reflects a use-after-free flaw enabling arbitrary code execution with high impact to confidentiality, integrity, and availability. The local attack vector (AV:L) acknowledges that exploitation requires file system access or document delivery. The requirement for user interaction (UI:R) prevents automatic exploitation but does not substantially lower risk given the ubiquity of Acrobat and prevalence of phishing. No privilege escalation is needed (PR:N), meaning a regular user's session is sufficient for code execution. The attack complexity is low (AC:L), indicating the vulnerability is likely straightforward to exploit once triggered.

Frequently asked questions