CVE-2026-52584 in LibJXL
Summary
by MITRE • 07/17/2026
Buffer Overflow vulnerability in libjxl v.0.11.2 and before allows a local attacker to obtain sensitive information via the DecodeImageAPNG function
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Analysis
by VulDB Data Team • 07/17/2026
A critical buffer overflow vulnerability exists within the libjxl library version 0.11.2 and earlier releases, specifically within the DecodeImageAPNG function that processes portable network graphics format images. This vulnerability arises from insufficient bounds checking during the parsing of APNG image data structures, allowing an attacker to manipulate memory layout through crafted input files. The flaw stems from improper handling of image dimensions and frame data within the decompression routine, creating opportunities for stack-based buffer overflows that can be exploited by local attackers with write access to the system. When the library processes malformed APNG files containing oversized or malformed frame specifications, the DecodeImageAPNG function fails to validate input parameters properly, leading to memory corruption that can result in information disclosure or arbitrary code execution. The vulnerability maps to CWE-121 which describes stack-based buffer overflow conditions, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter through the potential for remote code execution via compromised applications using this library. The impact extends beyond simple information disclosure as the memory corruption can be leveraged to execute malicious code within the context of the vulnerable application, potentially escalating privileges or compromising system integrity. Applications that rely on libjxl for image processing including web browsers, image viewers, and document processing software become susceptible to exploitation when they handle user-supplied APNG files without proper input validation.
The technical implementation of this vulnerability occurs during the parsing phase where the library allocates memory buffers based on header information from the APNG file structure. When the frame dimensions exceed expected bounds or when the data stream contains malformed metadata, the allocation logic fails to account for potential integer overflows or excessive memory requests. The DecodeImageAPNG function performs iterative processing of image frames without adequate boundary checks on array indices and buffer sizes, creating predictable overflow conditions that can be systematically exploited. The vulnerability is particularly dangerous because it operates in a local context where an attacker already has write permissions to the system, making exploitation more straightforward than remote attacks requiring network access. Memory layout changes during the buffer overflow can expose sensitive data from adjacent memory locations including stack canaries, return addresses, and other security-critical information that may aid further exploitation attempts.
Organizations utilizing libjxl in their applications should immediately implement mitigations to prevent exploitation of this vulnerability. The most effective immediate solution involves upgrading to libjxl version 0.12.0 or later where the buffer overflow has been patched through proper input validation and bounds checking mechanisms. Additionally, deploying runtime protections such as address space layout randomization ASLR and stack canaries can help detect and prevent exploitation attempts. Input sanitization should be implemented at application layers that consume libjxl functionality to validate APNG file integrity before processing. Security monitoring systems should be configured to detect anomalous memory access patterns and potential buffer overflow indicators during image processing operations. The vulnerability demonstrates the importance of proper input validation in cryptographic and multimedia libraries, as these components often handle untrusted data from external sources and require rigorous security testing to prevent exploitation through memory corruption attacks.
The broader implications of this vulnerability extend to the entire ecosystem of applications that depend on libjxl for high-quality image processing capabilities. Web browsers using libjxl for JPEG XL format support become potential attack vectors for malicious websites that could host specially crafted images designed to exploit this flaw. Mobile applications, desktop software, and server-side image processing systems all face similar risks when they incorporate vulnerable versions of the library into their codebase. The vulnerability highlights the necessity of regular security updates and dependency management practices within software development lifecycles, particularly for libraries handling multimedia data where memory corruption vulnerabilities can have severe consequences. Organizations should establish automated monitoring systems to track library versions and promptly apply security patches when vulnerabilities are identified in their software dependencies. This incident underscores the critical importance of maintaining up-to-date cryptographic libraries and implementing comprehensive security testing protocols that include fuzzing and memory safety analysis to prevent similar buffer overflow conditions from affecting software systems.