CVE-2026-48291: Format Plugins Buffer Overflow Vulnerability

CVE-2026-48291 Overview

CVE-2026-48291 is a heap-based buffer overflow vulnerability affecting Adobe Format Plugins versions 1.1.2 and earlier. Successful exploitation allows arbitrary code execution in the context of the current user. The flaw requires user interaction, meaning a victim must open a crafted malicious file for the exploit to trigger. Adobe addressed the issue in security bulletin APSB26-65. The weakness is classified under CWE-122: Heap-based Buffer Overflow.

Critical Impact
Attackers can achieve arbitrary code execution under the privileges of the logged-in user by convincing a victim to open a malicious file processed by Format Plugins.

Affected Products

Adobe Format Plugins version 1.1.2
Adobe Format Plugins prior to 1.1.2
Applications integrating vulnerable Format Plugins components

Discovery Timeline

2026-06-09 - CVE-2026-48291 published to NVD
2026-06-10 - Last updated in NVD database

Technical Details for CVE-2026-48291

Vulnerability Analysis

The vulnerability is a heap-based buffer overflow in Adobe Format Plugins. Heap overflows occur when a program writes data beyond the bounds of a buffer allocated on the heap. The corruption can overwrite adjacent heap metadata, function pointers, or object virtual tables. Attackers leverage this corruption to redirect execution flow and run attacker-controlled code in the context of the user running the application. Because Format Plugins parse complex file structures, malformed data fields can trigger the out-of-bounds write during parsing.

Root Cause

The root cause is improper validation of size or length values during file parsing in Format Plugins versions 1.1.2 and earlier. When the plugin processes a malformed input, it allocates an undersized heap buffer or fails to bounds-check before writing data. This condition aligns with CWE-122. Refer to the Adobe Security Update APSB26-65 for vendor-confirmed technical details.

Attack Vector

The attack vector is local and requires user interaction. An attacker crafts a malicious file structured to trigger the overflow when parsed by Format Plugins. The attacker delivers the file through email attachments, drive-by downloads, instant messaging, or shared storage. When the victim opens the file, the parsing routine executes the embedded payload. The exploit runs with the privileges of the current user, enabling persistence, credential theft, or lateral movement.

No verified public proof-of-concept code is available at the time of publication. See the Adobe Security Update APSB26-65 for further technical guidance.

Detection Methods for CVE-2026-48291

Indicators of Compromise

Unexpected child processes spawned by applications loading Format Plugins after opening a document
Crash dumps or Windows Error Reporting events referencing Format Plugins modules
Outbound network connections originating from the host application immediately after file open
Suspicious files with format-plugin-supported extensions arriving via email or web downloads

Detection Strategies

Monitor process trees for anomalous child processes launched by Adobe applications loading Format Plugins
Inspect endpoint telemetry for memory corruption signatures, including heap allocator exceptions in Format Plugin modules
Correlate file-open events with subsequent process creation, script execution, or LOLBin invocation

Monitoring Recommendations

Enable detailed process creation logging (Windows Event ID 4688 with command line auditing) across endpoints
Forward EDR and Sysmon telemetry to a centralized analytics platform for behavioral correlation
Track file delivery channels including email gateways and web proxies for files targeting Format Plugins consumers

How to Mitigate CVE-2026-48291

Immediate Actions Required

Apply the Adobe security update referenced in APSB26-65 to all systems running Format Plugins
Inventory endpoints to identify installations of Format Plugins version 1.1.2 or earlier
Restrict opening of untrusted files from email, web downloads, and external media until patches are deployed

Patch Information

Adobe released a security update addressing CVE-2026-48291 in bulletin APSB26-65. Administrators should upgrade Format Plugins beyond version 1.1.2 according to vendor guidance. Validate patch deployment status with configuration management tooling and confirm the updated component version on representative endpoints.

Workarounds

Block delivery of file types parsed by Format Plugins at email and web gateways pending patch deployment
Enforce least-privilege user accounts to limit the impact of arbitrary code execution
Enable operating system exploit mitigations including Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR)
Use application allowlisting to prevent execution of unauthorized child processes from vulnerable applications

bash

# Configuration example
# Query installed Adobe Format Plugins version on Windows endpoints
Get-ItemProperty "HKLM:\Software\Adobe\Format Plugins" | Select-Object Version