CVE-2026-103641 in Red Hat
Summary
by MITRE • 10/01/2026
A flaw was found in GEGL. The Radiance HDR loader reads past the end of a memory-mapped image when an uncompressed scanline is shorter than the width declared in the file header. Opening a crafted HDR file crashes the application that uses the loader.
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Analysis
by VulDB Data Team • 10/01/2026
The vulnerability identified within the Generic Graphics Library, commonly known as GEGL, represents a critical out-of-bounds read condition located specifically within its Radiance High Dynamic Range image format loader. This component is responsible for parsing and rendering .hdr files, which are widely used in computer graphics to store high dynamic range imagery that captures a broader range of luminosity than standard formats like JPEG or PNG. The flaw arises from an insufficient validation mechanism when processing uncompressed scanlines within the file structure. Specifically, the parser fails to verify whether the actual length of the data corresponding to a single horizontal line of pixels matches the width value declared in the image header before attempting to read that data into memory buffers allocated based on the header's dimensions.
From a technical perspective, this logic error leads to an out-of-bounds read operation where the application attempts to access memory locations beyond the end of the mapped file segment or buffer when the compressed or uncompressed scanline data is shorter than expected. In many implementations involving memory-mapped files, reading past the allocated region can trigger segmentation faults on operating systems that enforce strict memory protection boundaries. Consequently, an attacker who crafts a malicious HDR image with mismatched header width and actual line length can induce a denial of service by causing the host application to crash abruptly. This is not merely a theoretical issue but a practical stability risk for any software integrating GEGL as its underlying graphics processing engine, including popular open-source tools like GIMP or specialized visualization applications that rely on this library for image ingestion.
The operational impact of this vulnerability extends beyond simple application instability. For end-users, the primary consequence is a denial of service resulting in data loss if unsaved work is present at the time of the crash. However, from a security architecture standpoint, out-of-bounds reads are often precursors to more severe exploits. While the immediate manifestation described is a crash, reading beyond buffer boundaries can potentially expose sensitive information stored in adjacent memory regions, such as stack variables or other process data, leading to potential information disclosure vulnerabilities depending on how the application handles subsequent operations with the corrupted state. This aligns closely with CWE-125, which defines out-of-bounds read errors that occur when software reads past the end of a buffer, and CWE-20, which covers improper input validation where external data is not adequately checked before processing.
In terms of threat modeling and attack classification, this vulnerability maps to MITRE ATT&CK technique T1496, Resource Hijacking, specifically under the sub-category of Denial of Service via application crashes caused by malformed inputs. It also reflects common patterns found in CWE-787 related to improper access control at memory boundaries. The exploitability relies on social engineering or automated distribution vectors where a victim is persuaded to open a specially crafted HDR file through email attachments, web downloads, or shared network drives. Since GEGL operates as a library rather than a standalone application with its own user interface, the attack surface includes any downstream software that links against it and fails to implement additional sanitization layers before passing data to the vulnerable loader function.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. The primary solution involves updating GEGL to a patched version where the Radiance HDR loader has been modified to strictly validate scanline lengths against header declarations prior to memory access operations. Developers integrating this library should ensure their build pipelines pull these security patches promptly. For organizations unable to update immediately, implementing input validation at the application layer is recommended; specifically, applications should verify file integrity and structure before invoking GEGL functions for parsing HDR images. Additionally, enabling sandboxing or restricted execution environments for image processing tasks can limit the blast radius of a potential crash, preventing it from affecting critical system resources or other sensitive processes running on the same host machine.