CVE-2026-112259 in GIMP
Summary
by MITRE • 10/19/2026
A flaw was found in GIMP. Importing a crafted SBZ palette without a color-model attribute can cause a NULL pointer dereference during string comparison, resulting in denial of service of the GIMP application.
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Analysis
by VulDB Data Team • 10/19/2026
The GNU Image Manipulation Program (GIMP) is a widely used open-source raster graphics editor that supports various file formats for importing and exporting images, palettes, and other assets. One such format involves SBZ files, which are compressed palette archives often derived from the GIMP native XCF or PGM palette structures but packaged in a ZIP-like container with specific metadata requirements. A critical vulnerability has been identified within the parsing logic responsible for handling these imported SBZ palette files. Specifically, when an attacker crafts an SBZ file that lacks the required color-model attribute, the application fails to properly validate input data before proceeding with string comparison operations during the initialization of the palette object. This oversight leads directly to a NULL pointer dereference, causing the GIMP process to crash unexpectedly and resulting in a denial of service condition for the user attempting to load the malicious file.
From a technical perspective, this vulnerability stems from insufficient validation of XML or JSON-like metadata embedded within the SBZ archive structure before it is processed by the core rendering engine. In many cases, palette definitions rely on explicit declarations of color space models such as RGB, CMYK, or grayscale to ensure correct interpretation of pixel values and alpha channels. When this attribute is missing, internal functions that expect a valid string pointer receive NULL instead. Subsequent calls to standard C library string comparison routines like strcmp operate on this null reference without checking for validity first. This classic programming error results in immediate segmentation faults or access violations depending on the operating system architecture, effectively terminating the application thread handling the import operation. The flaw highlights a broader issue in multimedia processing software where complex archive formats are parsed with assumptions about mandatory fields that may not always be enforced by upstream validators.
The operational impact of this vulnerability is primarily limited to local denial of service scenarios unless GIMP is integrated into automated pipelines or web-based interfaces that process untrusted inputs without sandboxing. For individual users, opening a malicious SBZ file will simply crash the application, potentially leading to loss of unsaved work if auto-save features are not enabled. However, in enterprise environments where image processing workflows involve batch imports from external sources, such as design agencies or media production studios, this flaw could disrupt productivity and require manual intervention to recover state. Furthermore, while a simple NULL pointer dereference typically does not allow for arbitrary code execution due to modern memory protection mechanisms like ASLR and DEP, it serves as an indicator of deeper input validation weaknesses that might be exploitable in other contexts if similar patterns exist elsewhere in the codebase.
This vulnerability aligns with CWE-476, which describes a NULL pointer dereference occurring when software attempts to use a null pointer where a non-null pointer is required. It also relates to CWE-20, Improper Input Validation, as the application fails to verify that all necessary attributes are present before processing them. In terms of cyber kill chain and ATT&CK mapping, this falls under Initial Execution via user interaction (T1204) if delivered through social engineering, or potentially Command and Control exfiltration vectors if combined with other flaws in future versions. Although currently classified as a denial-of-service issue, it underscores the importance of robust input sanitization practices in GUI applications that handle complex file formats.
To mitigate this risk, users should ensure they are running the latest version of GIMP where patches for this specific parsing logic have been applied. Developers and maintainers must enforce strict schema validation on all imported palette files to guarantee that mandatory attributes like color-model are present before any string operations are performed. Implementing defensive programming techniques such as null checks prior to pointer dereferencing can prevent crashes even if malformed data slips through initial filters. Additionally, integrating automated fuzz testing into the CI/CD pipeline for file parsers helps identify edge cases involving missing or corrupted metadata fields early in development cycles. Organizations relying on GIMP should also consider deploying application whitelisting solutions and restricting macro execution to reduce the attack surface associated with untrusted asset imports.