CVE-2026-13708 in Imager::File::JPEG
Summary
by MITRE • 07/06/2026
Imager::File::JPEG versions before 1.003 for Perl leak heap memory when reading a JPEG with repeated APP13 markers in i_readjpeg_wiol.
i_readjpeg_wiol walks the marker list libjpeg returns and, for each APP13 marker, allocates a new buffer with *iptc_itext = mymalloc(...) and overwrites the previous pointer without freeing it. Only the final payload is later turned into a Perl scalar and freed, so a JPEG with N such markers leaks the first N-1 payloads on every read.
In a long-lived process, such as an upload or thumbnailing service, repeated reads accumulate these leaks and exhaust available memory, a denial of service.
The same handler ships bundled in the Imager distribution, where versions before 1.032 are affected and the fix ships in 1.032.
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Analysis
by VulDB Data Team • 07/06/2026
This vulnerability represents a classic heap memory leak in the Imager::File::JPEG Perl module affecting versions prior to 1.003. The flaw occurs during JPEG file processing when the i_readjpeg_wiol function encounters repeated APP13 markers within image data. The module utilizes the libjpeg library for parsing JPEG structures and subsequently processes these markers through its own implementation. When multiple APP13 markers are present, the function iterates through the marker list returned by libjpeg but fails to properly manage memory allocation for each marker's payload.
The technical execution of this vulnerability stems from improper memory management within the i_readjpeg_wiol handler where it allocates new buffers using mymalloc() for each APP13 marker encountered. The implementation overwrites previous pointer values without freeing the associated memory, creating a memory leak pattern where each subsequent marker allocation discards the previous buffer reference while leaving the old memory allocated. This behavior specifically affects IPTC metadata processing within JPEG files, as APP13 markers typically contain IPTC data that the module attempts to extract and convert into Perl scalar format.
The operational impact of this vulnerability becomes significant in long-running processes such as web services handling image uploads or automated thumbnail generation systems. Each time a vulnerable module reads a JPEG file containing multiple APP13 markers, it accumulates memory leaks corresponding to the number of repeated markers minus one. This progressive memory consumption eventually leads to system resource exhaustion and denial of service conditions, making it particularly dangerous in production environments where continuous image processing occurs. The vulnerability is classified under CWE-401 as a failure to release memory resources, representing a direct violation of proper memory management practices.
The fix implemented in version 1.032 addresses this issue by ensuring proper memory cleanup during marker processing, preventing the accumulation of unused buffer allocations. This remediation aligns with ATT&CK technique T1499.004 for resource exhaustion attacks, where attackers could potentially exploit this vulnerability to consume system resources through repeated image processing operations. Organizations running services that process JPEG files should prioritize upgrading to version 1.032 or later, as the vulnerability creates a persistent memory leak that can be exploited to degrade service availability. The affected scope extends beyond simple file reading to include any application using Imager::File::JPEG for image processing, particularly web applications, content management systems, and automated image handling services that process user-uploaded JPEG files containing IPTC metadata with repeated APP13 markers.