CVE-2026-106064 in Red Hat
Summary
by MITRE • 10/07/2026
A heap-based buffer overflow was found in GIMP’s GIF export plug-in. Exporting an image with very large width and height can cause 32-bit overflow when computing the pixel buffer size. The plug-in allocates a buffer based on the wrapped value while GEGL writes using the true image extent, rooted in integer overflow
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as CVE-2019-6758 represents a critical heap-based buffer overflow within the Graphics Interchange Format export plugin of GIMP. This flaw stems from an integer overflow condition that occurs during the calculation of memory allocation sizes for image buffers. Specifically, when processing images with exceptionally large width and height dimensions, the arithmetic operation used to determine the total pixel buffer size exceeds the maximum value representable by a 32-bit signed or unsigned integer. Instead of triggering an error or rejecting the oversized input, the application wraps around this limit, resulting in a significantly smaller allocated memory block than what is actually required for storing the image data.
From a technical perspective, the root cause lies in the lack of proper bounds checking and overflow detection during the buffer size computation phase. The plug-in allocates heap memory based on the wrapped integer value, which is drastically reduced compared to the true extent of the image dimensions. However, subsequent operations within GEGL, GIMP’s underlying graph-based image processing library, proceed under the assumption that sufficient memory has been allocated for the full image resolution. Consequently, when GEGL attempts to write pixel data into this undersized buffer, it writes beyond the boundaries of the allocated heap region. This out-of-bounds write operation corrupts adjacent memory structures on the heap, potentially overwriting metadata such as allocation headers or pointers used by subsequent malloc and free calls.
The operational impact of this vulnerability is severe due to its potential for remote code execution if an attacker can trick a user into opening a specially crafted GIF file. By exploiting the heap corruption, an adversary may achieve arbitrary read and write primitives within the process memory space. This capability allows for the bypassing of modern security mitigations such as Address Space Layout Randomization and Data Execution Prevention. The vulnerability aligns with CWE-190 Integer Overflow or Wraparound, which describes scenarios where arithmetic operations exceed the capacity of a data type without proper validation. Furthermore, it maps to ATT&CK technique T1203 Exploitation for Client Execution, as the attack vector typically involves social engineering tactics like phishing emails containing malicious attachments that trigger the vulnerability upon opening in GIMP.
Mitigation strategies primarily involve updating to patched versions of GIMP where developers have implemented rigorous checks for integer overflow conditions before memory allocation occurs. Input validation should be strengthened to reject image dimensions that would result in buffer sizes exceeding safe limits or causing arithmetic wraparound. Additionally, enabling heap protection mechanisms such as stack canaries and using compilers with built-in overflow detection flags like -ftrapv during the build process can help identify similar issues early in development. For end-users, it is advisable to avoid opening GIF files from untrusted sources until the software has been updated to address this specific flaw.