LibRaw Heap-Based Buffer Overflow Vulnerability (CVE-2026-24660)

A heap-based buffer overflow vulnerability, identified as CVE-2026-24660, has been discovered in LibRaw, specifically affecting the x3f_load_huffman functionality in commit d20315b. The vulnerability arises from improper handling of a crafted input file, leading to a heap buffer overflow condition. An attacker can exploit this vulnerability by providing a malicious file designed to trigger the overflow during the Huffman decoding process. This could potentially allow an attacker to execute arbitrary code or cause a denial-of-service condition. This vulnerability impacts applications that utilize LibRaw for processing image files, particularly those dealing with potentially untrusted or externally sourced image data. Defenders should be aware of this vulnerability and take steps to mitigate the risk by updating to patched versions of LibRaw or implementing input validation measures.

Attack Chain

1. An attacker crafts a malicious image file in a format processed by LibRaw. This file is specifically designed to exploit the x3f_load_huffman function.
2. The vulnerable application using LibRaw processes the malicious image file.
3. During the Huffman decoding process within x3f_load_huffman, the crafted file triggers an integer overflow, leading to a heap buffer overflow.
4. Data is written beyond the allocated buffer on the heap.
5. This overwrite can corrupt adjacent heap metadata, potentially leading to control over memory allocation.
6. The attacker gains the ability to overwrite function pointers or other critical data structures on the heap.
7. By manipulating these structures, the attacker can redirect program execution flow.
8. The attacker achieves arbitrary code execution within the context of the application using LibRaw.

Impact

Successful exploitation of CVE-2026-24660 can lead to arbitrary code execution, potentially allowing an attacker to gain full control over the affected system. The vulnerability resides in a widely used library, potentially impacting a large number of applications that depend on LibRaw for image processing. Exploitation could result in data breaches, system compromise, or denial-of-service conditions. Given the CVSS v3.1 base score of 8.1, this vulnerability poses a significant risk and requires prompt attention.

Recommendation

• Apply patches or updates to LibRaw to versions containing the fix for CVE-2026-24660 to remediate the vulnerability.
• Implement input validation and sanitization measures for image files processed by LibRaw to detect and prevent malicious files from triggering the buffer overflow.
• Monitor applications using LibRaw for unexpected crashes or abnormal behavior that could indicate exploitation attempts.
• Deploy the Sigma rule “Detect LibRaw Heap Overflow Attempt” to detect exploitation attempts by monitoring process creation events.
• Consider implementing Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) to further mitigate the impact of successful exploitation.