CVE-2026-57246: Foxit PDF Editor & Reader Vulnerability – Local Privilege Escalation

Technical summary

This vulnerability stems from insufficient argument validation (CWE-120) in the signature verification process. When a specially crafted PDF object is processed, JavaScript code initiates signature verification, but the plugin fails to validate the abnormal string data during the copy operation. This missing validation check allows memory corruption or buffer-related conditions that can crash the application. The CVSS 3.1 score of 7.8 reflects local access requirement (AV:L), low complexity exploitation (AC:L), no privilege escalation needed (PR:N), user interaction requirement (UI:R), and impacts to confidentiality, integrity, and availability (C:H/I:H/A:H).

Business impact

Organizations relying on Foxit PDF products for document handling face potential data exposure and workflow disruption. If an attacker crafts a malicious PDF and tricks a user into opening it, the crash could lead to temporary denial of service, loss of unsaved work, and in multi-user environments, cascading failures. The high impact on confidentiality and integrity suggests potential for data exfiltration or document tampering before the crash occurs. Environments handling sensitive PDF documents—legal, financial, healthcare—should prioritize remediation.

Affected systems

The vulnerability affects Foxit PDF Editor (all versions until patched), Foxit PDF Reader (all versions until patched), and Microsoft Windows systems hosting these applications. The Windows listing indicates the vulnerability may interact with OS-level libraries or be exploitable through Windows-specific vectors. Organizations should verify exact affected versions against Foxit's official security advisory and Windows patch status.

Exploitability

Exploitation requires local system access and active user interaction. An attacker must deliver a crafted PDF (via email, malicious website, or removable media) and convince a user to open it in Foxit PDF Editor or Reader. The low complexity (AC:L) indicates no special conditions or bypass techniques are needed once the user opens the file. The lack of CISA KEV inclusion suggests no evidence of active in-the-wild exploitation as of the published date, but the attack vector is practical and user-centric, not requiring elevated privileges to initiate.

Remediation

Apply patches from Foxit and Microsoft as they become available. Verify patched versions directly from official vendor advisories. Until patching is complete, implement user awareness training to avoid opening PDFs from untrusted sources and restrict PDF opening permissions in group policy where feasible. Consider disabling JavaScript execution in PDF readers if business workflows allow. Maintain endpoint detection and response (EDR) tools configured to alert on unexpected application crashes in PDF software.

Patch guidance

Monitor Foxit's official security advisory pages for CVE-2026-57246 patch releases for both PDF Editor and PDF Reader. Microsoft will likely address this through Windows Update; check KB articles once released. Deploy patches in a staged approach: test in non-production environments first, prioritize systems handling untrusted PDFs, and track completion across all affected products. Verify patch installation by checking software version numbers post-deployment.

Detection guidance

Monitor for abnormal termination of Foxit PDF Editor/Reader processes, particularly those preceded by JavaScript execution within PDF documents. Log file access patterns to identify which PDFs triggered crashes. Network-based detection is limited since the vulnerability is local; focus on endpoint logs. EDR tools should flag repeated application crashes from PDF processing. Consider enabling PDF sandboxing features if available in your Foxit deployment to contain exploitation attempts.

Why prioritize this

Despite the lack of KEV status and no confirmed active exploitation, the 7.8 CVSS score and high impact on all three CIA triads warrant prioritization. The user-interaction requirement and local-access vector reduce urgency relative to remote vulnerabilities, but the practical attack scenario—malicious PDF delivery—is common. Organizations should patch within 30 days, sooner if PDFs are a critical workflow component.

Risk score, explained

The CVSS 7.8 HIGH severity reflects that while local access and user interaction are required, successful exploitation results in confidentiality, integrity, and availability compromise. The lack of complexity in crafting the malformed object and the low barrier to user interaction (tricking someone to open a PDF) push the score into HIGH territory. This is not a CRITICAL remote-code-execution vector, but the breadth of impact and ease of delivery elevate it above MEDIUM.

Frequently asked questions