CVE-2025-54218: Adobe InCopy RCE Vulnerability

CVE-2025-54218 Overview

CVE-2025-54218 is an out-of-bounds write vulnerability [CWE-787] in Adobe InCopy versions 20.4, 19.5.4, and earlier. Successful exploitation allows arbitrary code execution in the context of the current user. The flaw requires user interaction: a victim must open a malicious file crafted by an attacker. Adobe published the advisory APSB25-80 to address this issue across both Windows and macOS installations of InCopy.

Critical Impact
Attackers who convince a user to open a crafted document can execute arbitrary code with the privileges of the current user, leading to full compromise of the user session on Windows or macOS hosts.

Affected Products

Adobe InCopy 20.4 and earlier (20.x branch)
Adobe InCopy 19.5.4 and earlier (19.x branch)
Microsoft Windows and Apple macOS installations of the above versions

Discovery Timeline

2025-08-12 - CVE-2025-54218 published to NVD
2025-08-13 - Last updated in NVD database

Technical Details for CVE-2025-54218

Vulnerability Analysis

The vulnerability is an out-of-bounds write [CWE-787] in Adobe InCopy, a desktop application used by editorial workflows alongside Adobe InDesign. InCopy parses several proprietary and standard document formats. When the parser processes a malformed file, it writes data past the bounds of an allocated buffer.

Out-of-bounds writes corrupt adjacent memory structures. Attackers shape the malformed input to overwrite function pointers, virtual table pointers, or heap metadata. This corruption yields control of the instruction pointer and enables arbitrary code execution in the InCopy process.

The attack requires local access in the sense that the file must be opened on the victim's system. Authentication is not required, and the resulting code runs with the privileges of the user who opened the file.

Root Cause

The root cause is missing or incorrect bounds validation during file parsing. InCopy fails to verify that an offset, length, or index supplied by the input file remains within the bounds of the destination buffer before writing. Adobe has not published parser-level technical details. Refer to the Adobe InCopy Security Advisory APSB25-80 for vendor-confirmed details.

Attack Vector

An attacker crafts a malicious InCopy-compatible document and delivers it through phishing email, file-sharing platforms, or compromised collaboration workflows shared between editors and designers. When the victim opens the file in a vulnerable version of InCopy, the parser triggers the out-of-bounds write and executes attacker-controlled code. No network exposure is required, and the application requires no elevated privileges to be exploited.

No public proof-of-concept exploit code is available for CVE-2025-54218 at the time of writing. See the vendor advisory for technical details.

Detection Methods for CVE-2025-54218

Indicators of Compromise

Unexpected child processes (for example, cmd.exe, powershell.exe, bash, or osascript) spawned by InCopy.exe or the macOS InCopy bundle.
InCopy process crashes or Windows Error Reporting (WerFault.exe) events correlated with opening third-party documents.
Inbound InCopy documents (.icml, .incx, .indd-linked assets) from untrusted senders, especially those triggering antivirus heuristics.
Outbound network connections from the InCopy process to unfamiliar hosts shortly after a document is opened.

Detection Strategies

Hunt for process-lineage anomalies where InCopy spawns shell interpreters, scripting hosts, or LOLBins (rundll32.exe, mshta.exe, wscript.exe).
Alert on InCopy process memory anomalies, including RWX allocations or thread creation in unexpected modules.
Inspect inbound email attachments and shared-drive uploads for InCopy file extensions and apply sandbox detonation before delivery.

Monitoring Recommendations

Forward endpoint process, file, and network telemetry to a central data lake or SIEM and retain at least 90 days for retrospective hunts.
Monitor InCopy version inventory across managed Windows and macOS endpoints to identify hosts still running 20.4 or 19.5.4 and earlier.
Track user reports of InCopy crashes and correlate with document provenance to surface targeted attacks early.

How to Mitigate CVE-2025-54218

Immediate Actions Required

Apply the Adobe InCopy updates referenced in APSB25-80 to all Windows and macOS endpoints running affected versions.
Inventory installed InCopy versions using software asset management or endpoint telemetry, and prioritize hosts used by editorial and design teams.
Restrict opening of InCopy documents originating from outside the organization until patching is verified.
Reinforce user awareness: instruct staff not to open unsolicited InCopy or InDesign attachments.

Patch Information

Adobe addressed CVE-2025-54218 in Adobe InCopy versions released alongside security bulletin APSB25-80. Users on the 20.x branch must upgrade beyond 20.4, and users on the 19.x branch must upgrade beyond 19.5.4. Adobe Creative Cloud Desktop and enterprise deployment tools (Adobe Admin Console, RUM, SCCM packages) can deliver the fixed builds. See the Adobe InCopy Security Advisory for the exact fixed version numbers and download links.

Workarounds

Block or quarantine InCopy file extensions at the email gateway and detonate them in a sandbox before delivery to end users.
Configure application allowlisting to prevent InCopy from launching child processes such as shells and scripting interpreters.
Run InCopy under a standard (non-administrator) user account to limit the impact of successful exploitation.

bash

# Example: list Adobe InCopy installations on Windows endpoints (PowerShell)
Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\*' |
  Where-Object { $_.DisplayName -like 'Adobe InCopy*' } |
  Select-Object DisplayName, DisplayVersion, InstallLocation