CVE-2026-109276 in ImageMagick
Summary
by MITRE • 10/12/2026
ImageMagick before 6.9.13-57 and 7.x before 7.1.2-32 contains an incomplete cleanup flaw in the JNG decoder that fails to remove temporary files when processing crafted input. Attackers can submit crafted JNG files for processing to repeatedly leak temporary files, consuming disk space and degrading availability.
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Analysis
by VulDB Data Team • 10/12/2026
The vulnerability identified within ImageMagick versions prior to 6.9.13-57 and 7.x before 7.1.2-32 represents a critical resource management failure located specifically in the JPEG Network Graphics, or JNG, decoder module. This flaw stems from an incomplete cleanup procedure that occurs during the processing of image data. When ImageMagick handles input files, it often creates temporary intermediate files to store processed segments before assembling the final output. In this specific instance, the software fails to properly delete these temporary artifacts when a crafted or malformed JNG file is encountered. This oversight means that while the primary decoding operation may proceed or fail depending on subsequent logic, the auxiliary files generated during the process are left behind in the system's temporary directory structure rather than being purged as intended by standard operational protocols.
From a technical perspective, this issue classifies under CWE-377, which describes Insecure Temporary File Creation and Management. The root cause lies in the error handling paths of the JNG decoder implementation. Typically, secure software design dictates that any resource allocated during an operation must be released upon completion or failure to prevent state corruption or resource exhaustion. Here, the lack of a robust cleanup mechanism means that every invocation of the vulnerable code path results in persistent file system modifications. Attackers can exploit this by submitting specially crafted JNG files designed to trigger specific decoding paths where the temporary file creation occurs but the subsequent deletion routine is bypassed due to the malformed input structure or unexpected state transitions within the decoder logic.
The operational impact of this vulnerability is primarily centered on resource exhaustion and denial of service conditions. By repeatedly submitting these crafted inputs, an attacker can cause a rapid accumulation of orphaned temporary files on the host system. This behavior leads to significant disk space consumption, which can eventually fill up available storage partitions. As free disk space diminishes, the overall performance of the server or application hosting ImageMagick degrades significantly. In severe cases, this resource depletion can render the service unavailable for legitimate users who require access to image processing capabilities, effectively achieving a denial-of-service state without needing to exploit memory corruption or execute arbitrary code directly through this specific vector.
This vulnerability aligns with MITRE ATT&CK technique T1496, Resource Hijacking, specifically under the sub-technique of Disk Wipe or Overuse via File Deletion and Creation. While often associated with ransomware or destructive malware, in this context it is utilized as a disruptive mechanism to degrade system availability rather than for data exfiltration or encryption. The attack pattern involves leveraging legitimate software functionality against itself to consume infrastructure resources, making detection challenging because the activity appears as normal file creation until the volume becomes anomalous and impacts system stability.
Mitigation strategies focus on immediate version upgrades and defensive configuration adjustments. Organizations running affected versions of ImageMagick should upgrade immediately to version 6.9.13-57 or later for the legacy branch, or version 7.1.2-32 and above for the current major release line, as these updates include patches that enforce proper cleanup routines regardless of input validity. Additionally, administrators can implement operational mitigations such as configuring system-level temporary directory quotas to limit the maximum size of temp folders, thereby containing the impact of any residual exploitation attempts until patching is completed. Regular monitoring of disk usage trends and implementing alerts for unusual spikes in file creation rates within application-specific directories can also provide early warning indicators of potential abuse of this flaw.