CVE-2026-2047: GIMP ICNS File Parsing RCE Vulnerability

CVE-2026-2047 Overview

CVE-2026-2047 is a heap-based buffer overflow vulnerability in GIMP's ICNS file parsing functionality that enables remote code execution. This vulnerability allows remote attackers to execute arbitrary code on affected installations of GIMP. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the parsing of ICNS files. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process.

Critical Impact

Remote attackers can achieve arbitrary code execution by tricking users into opening malicious ICNS files, potentially leading to complete system compromise under the context of the current user.

Affected Products

• GIMP version 3.0.6
• GIMP installations with ICNS file parsing enabled
• Systems where users open untrusted image files

Discovery Timeline

• 2026-02-20 - CVE-2026-2047 published to NVD
• 2026-02-24 - Last updated in NVD database

Technical Details for CVE-2026-2047

Vulnerability Analysis

This heap-based buffer overflow vulnerability (CWE-122, CWE-787) occurs during the parsing of Apple Icon Image format (ICNS) files in GIMP. The vulnerability was discovered through the Zero Day Initiative program and tracked as ZDI-CAN-28530.

The flaw stems from insufficient bounds checking when processing user-controlled data from ICNS files. When GIMP parses a specially crafted ICNS file, it fails to properly validate the length of data before copying it to a heap-allocated buffer. This allows an attacker to overflow the buffer, corrupting adjacent heap memory and potentially gaining control of program execution flow.

Exploitation requires user interaction—the victim must open a malicious ICNS file or visit a webpage that serves malicious content. Upon successful exploitation, the attacker achieves code execution within the context of the GIMP process, inheriting all user permissions and access rights.

Root Cause

The root cause is improper validation of user-supplied data length in the ICNS file parsing routine. The code fails to verify that the data length specified in the ICNS file structure does not exceed the allocated buffer size before performing memory copy operations. This missing boundary check allows heap memory corruption when processing malformed ICNS files with oversized data fields.

Attack Vector

The attack vector is local, requiring user interaction. An attacker must craft a malicious ICNS file containing specially constructed data that triggers the buffer overflow when parsed. The attack can be delivered through:

1. Direct file delivery: Sending the malicious ICNS file via email, file sharing, or other distribution methods
2. Web-based delivery: Hosting the malicious file on a compromised or attacker-controlled website where the victim may download and open it
3. Social engineering: Convincing users to open seemingly legitimate image files that contain the malicious payload

The vulnerability manifests when GIMP processes the ICNS file header and attempts to copy image data into a heap buffer without properly validating the declared data size against the actual buffer allocation. Detailed technical information can be found in the Zero Day Initiative Advisory ZDI-26-120.

Detection Methods for CVE-2026-2047

Indicators of Compromise

• Unexpected GIMP process crashes when opening ICNS files
• GIMP processes spawning unexpected child processes or network connections
• Presence of suspicious ICNS files with abnormally large or malformed headers
• Memory access violations or heap corruption errors in GIMP crash logs

Detection Strategies

• Monitor for GIMP processes exhibiting abnormal behavior after file operations
• Implement file scanning for malformed ICNS files with mismatched size declarations
• Deploy endpoint detection rules to identify heap spray patterns associated with ICNS exploitation
• Track GIMP processes for unusual system calls or privilege changes following file open operations

Monitoring Recommendations

• Enable crash dump collection and analysis for GIMP processes to identify exploitation attempts
• Monitor file system activity for suspicious ICNS file downloads or transfers
• Implement network monitoring for connections initiated by GIMP processes to unknown destinations
• Deploy SentinelOne agents to detect and block exploit attempts targeting this vulnerability

How to Mitigate CVE-2026-2047

Immediate Actions Required

• Update GIMP to the latest patched version immediately
• Warn users not to open ICNS files from untrusted or unknown sources
• Consider temporarily blocking ICNS file types at email gateways and web proxies
• Enable SentinelOne's behavioral AI protection to detect exploitation attempts

Patch Information

GIMP has released a security patch addressing this vulnerability. The fix is available in the GitLab GIMP Merge Request #2600. The patch adds proper length validation before copying user-supplied data to heap buffers during ICNS file parsing.

Organizations should prioritize updating to the patched version. The specific commit addressing this vulnerability is dd2faac351f1ff2588529fedc606e6a5f815577c.

Workarounds

• Disable or remove ICNS file type associations in GIMP until patching is complete
• Implement file filtering at organizational boundaries to block ICNS files from external sources
• Use application sandboxing to limit the impact of potential exploitation
• Configure endpoint protection solutions to monitor GIMP processes for suspicious activity

# Verify GIMP version and check for vulnerable installations
gimp --version

# On Linux systems, check if GIMP is installed and its version
dpkg -l | grep gimp    # Debian/Ubuntu
rpm -qa | grep gimp    # RHEL/CentOS

# Block ICNS file associations temporarily (Linux)
xdg-mime default none.desktop image/x-icns