CVE-2026-80101 in Red Hat
Summary
by MITRE • 08/26/2026
A flaw was found in the file-xwd plugin in GIMP. When processing a specially crafted XWD image file, the plugin validates the image width and bytes-per-line parameters independently rather than ensuring their combined values are consistent with the allocated buffer size. This incorrect validation leads to improper bounds checking, causing a heap out-of-bounds read. This issue can result in an application crash, leading to a denial of service, or a limited information disclosure of heap memory contents into the produced image.
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified within the file-xwd plugin for GIMP represents a critical failure in input validation logic during the processing of X Window System Dump (XWD) image files. This flaw stems from an architectural oversight where the application validates the image width and bytes-per-line parameters as isolated entities rather than evaluating their combined mathematical relationship against the actual size of the allocated memory buffer. In standard image processing workflows, these two variables are intrinsically linked; the total data required for a single row is calculated by multiplying the pixel dimensions by the byte depth per channel, which must align with the bytes-per-line specification provided in the file header. By treating them independently, the software fails to detect when the specified parameters exceed the bounds of the memory region reserved for that specific image frame. This lack of holistic validation creates a scenario where the application proceeds to read data from heap memory locations that were not intended to be accessed by this particular operation.
From a technical perspective, this misconfiguration results in a heap out-of-bounds read vulnerability. When GIMP processes a maliciously crafted XWD file with manipulated width or bytes-per-line values, it attempts to copy pixel data into the output buffer without verifying if the source memory addresses fall within the allocated limits. This improper bounds checking allows the application to leak sensitive information from adjacent regions of the heap. The operational impact is twofold: first, accessing invalid memory can trigger segmentation faults or other exceptions that cause the GIMP application to crash immediately, resulting in a denial of service for users attempting to open such files. Second, and more critically, the uncontrolled read operation can expose contents of the process's private heap memory into the newly generated image file. This constitutes an information disclosure vulnerability where internal state data, potentially including cryptographic keys, passwords, or other user-sensitive information stored in nearby memory blocks, is inadvertently written to disk via the output image.
This type of flaw aligns with Common Weakness Enumeration (CWE) categories such as CWE-125 Out-of-bounds Read and CWE-20 Improper Input Validation. The attack vector typically involves an attacker distributing a specially crafted XWD file through email, web downloads, or shared network drives, relying on the victim to open it within GIMP. In terms of the MITRE ATT&CK framework, this behavior is consistent with techniques involving data exfiltration from local systems via memory scraping, often categorized under Initial Access if used as a delivery mechanism for further exploitation, though primarily here it serves as an Information Disclosure vector. The severity is heightened by the fact that GIMP is widely used in professional and creative environments where users frequently handle images from untrusted sources or collaborate with external parties who may not sanitize their file outputs properly.
Mitigation strategies must focus on both immediate patching and long-term defensive coding practices. Users should immediately update to a version of GIMP that includes the fix for this specific validation logic in the file-xwd plugin. For developers, the remediation requires implementing strict cross-parameter validation where the sum or product of width, height, bytes-per-line, and bit depth is explicitly compared against the total buffer size before any memory copy operations occur. Additionally, incorporating static analysis tools that detect out-of-bounds access patterns during development can help prevent similar issues in future releases. Security teams should also consider implementing sandboxing for image processing applications to limit the impact of potential heap corruption or information leaks, ensuring that even if a vulnerability is exploited, the blast radius remains contained within the application process and does not compromise the host operating system's integrity.