CVE-2026-79910 in Acrobat Reader
Summary
by MITRE • 09/09/2026
Acrobat Reader is affected by an out-of-bounds read vulnerability that could lead to disclosure of sensitive memory. An attacker could leverage this vulnerability to disclose sensitive information. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
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Analysis
by VulDB Data Team • 09/10/2026
The identified vulnerability represents a critical security flaw within Adobe Acrobat Reader, specifically categorized as an out-of-bounds read condition. This type of memory corruption error occurs when the application attempts to access data at a memory address that lies outside the intended buffer boundary. In this specific instance, the software fails to properly validate input parameters or array indices before performing read operations on allocated memory regions. Such failures are typically rooted in improper bounds checking logic within the parser routines responsible for processing document structures, fonts, or embedded objects. The consequence of this flaw is that an attacker can craft a malicious PDF file containing specially constructed data elements designed to trigger the erroneous memory access sequence. When a victim opens this crafted file, Acrobat Reader processes the malformed input and executes the out-of-bounds read operation, thereby allowing the application to retrieve and potentially expose contents from adjacent memory locations that were not intended for disclosure.
The operational impact of this vulnerability centers on information leakage rather than immediate code execution or system compromise. By exploiting the out-of-bounds read condition, an attacker can force Acrobat Reader to dump sensitive data residing in nearby memory buffers into a location accessible by the malicious payload. This disclosed information may include cryptographic keys, session tokens, passwords, or other confidential data currently held in the application's memory space. While this does not directly grant remote code execution privileges, it significantly lowers the barrier for further exploitation stages such as heap spraying or arbitrary read attacks that could eventually lead to full system compromise. The severity of this impact is compounded by the fact that Acrobat Reader is a widely deployed enterprise and consumer tool, making successful exploits potentially impactful across large user bases if not promptly mitigated through patches or configuration changes.
From a classification perspective, this vulnerability aligns with Common Weakness Enumeration identifier CWE-125, which describes out-of-bounds read scenarios where software reads data past the end of a buffer without proper validation. This weakness is often exploited in conjunction with other memory corruption flaws to achieve arbitrary information disclosure or to facilitate more complex attack chains involving heap metadata manipulation. In terms of tactical mapping under the MITRE ATT&CK framework, this vulnerability supports techniques related to Collection and Credential Access, specifically leveraging software vulnerabilities for data exfiltration. Attackers would likely utilize social engineering tactics to deliver the malicious file, as direct exploitation requires user interaction. The delivery mechanism typically involves phishing emails or compromised websites that prompt users to open seemingly legitimate documents containing embedded exploits targeting the Acrobat Reader engine.
Mitigation strategies must address both immediate remediation and long-term defensive posture improvements. The primary defense is the timely installation of vendor-provided security patches that correct the bounds checking logic within the affected versions of Adobe Acrobat Reader. Organizations should prioritize patching endpoints running this software, particularly those with internet-facing roles or handling sensitive documents. In environments where immediate patching is not feasible due to compatibility concerns, network-level controls such as web proxies and email gateways can be configured to detect and block known malicious PDF signatures associated with exploit kits targeting this vulnerability. Additionally, enabling Protected Mode in Acrobat Reader restricts the application's access to system resources, thereby limiting the potential impact of any successful memory disclosure by isolating the process from critical operating system components. User awareness training is also essential to reduce the likelihood of user interaction with untrusted documents, as exploitation requires a victim to actively open the malicious file. Regular auditing of installed software versions and disabling unnecessary features such as JavaScript execution in PDFs can further reduce the attack surface available to adversaries seeking to leverage this or similar memory corruption flaws.