CVE-2026-111149 in FreeImage
Summary
by MITRE • 10/15/2026
FreeImage (danoli3 fork) through 3.19.23 contains a heap out-of-bounds read vulnerability in Unpack32Bits() in PluginPICT.cpp because rowBytes is never checked against the file-controlled PixMap width. Attackers can supply a crafted PICT file with a truncated or undersized rowBytes to over-read up to 64 KiB of heap, leaking memory into decoded pixels or crashing the process.
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Analysis
by VulDB Data Team • 10/15/2026
The vulnerability identified in FreeImage, specifically within the danoli3 fork through version 3.19.23, represents a critical security flaw located in the image processing logic for PICT format files. This defect is situated within the Unpack32Bits function found in PluginPICT.cpp and constitutes a heap-based out-of-bounds read vulnerability. The root cause of this issue lies in a fundamental failure to validate input data integrity before performing memory access operations. Specifically, the software fails to verify that the rowBytes value provided by the PICT file header is consistent with or sufficient for the declared PixMap width. In image processing libraries, rowBytes typically defines the number of bytes allocated per horizontal line of pixels in an image buffer. When this parameter is manipulated by a malicious actor, it creates a discrepancy between the expected memory layout and the actual data available, leading to unsafe memory access patterns that compromise system stability and confidentiality.
From a technical perspective, the exploitation mechanism relies on crafting a PICT file where the rowBytes field is intentionally set to a truncated or undersized value relative to the image width defined in the PixMap structure. During the decoding process, the Unpack32Bits function iterates through pixel data based on these parameters without performing adequate boundary checks against the actual allocated heap memory size. Consequently, when the decoder attempts to read pixel data for each row, it proceeds beyond the bounds of the originally allocated buffer if the file claims a width that requires more bytes than are actually present or validly accessible due to the manipulated rowBytes value. This allows an attacker to trigger a read operation that extends up to 64 KiB past the intended memory boundary. Such over-reads do not modify data but rather expose sensitive information residing in adjacent heap regions, which may contain stack canaries, pointers to other objects, or even parts of the operating system's memory space depending on the allocation context and runtime environment.
The operational impact of this vulnerability is significant for any application that integrates FreeImage for image processing tasks involving PICT files. If an attacker successfully exploits this flaw by convincing a victim to open a maliciously crafted file, they can achieve information disclosure through heap leakage. The leaked memory contents could potentially be used in subsequent exploitation phases, such as bypassing address space layout randomization or constructing more complex attacks like use-after-free scenarios if combined with other vulnerabilities. Furthermore, the vulnerability poses a risk of denial-of-service conditions. Depending on how the operating system handles invalid memory accesses and whether specific protections are enabled, reading from unmapped or protected heap regions can cause the application process to crash abruptly. This instability disrupts service availability for users relying on image viewing or processing software that utilizes this library.
In terms of industry classification standards, this vulnerability aligns with CWE-125, which describes Out-of-bounds Read vulnerabilities where a program reads data past the end or before the beginning of the intended buffer. It also relates to CWE-20, Improper Input Validation, as the core failure is the lack of sanitization and verification of external file parameters against expected constraints. From an offensive security perspective, this behavior maps to ATT&CK technique T1567.002, specifically Exfiltration Over Unencrypted Non-C2 Protocol if the leaked data is transmitted out, or more accurately T1005, Data from Local System, as it involves direct memory scraping without network exfiltration in its immediate form. The attack vector typically falls under ATT&CK technique T1203, Exploitation for Client Execution, assuming the vulnerability is triggered by a user opening a file within an application context rather than through automated server-side processing alone.
Mitigation strategies must focus on both immediate patching and long-term defensive coding practices. The primary remediation is to upgrade FreeImage to a version that includes patches addressing this specific validation logic in PluginPICT.cpp. Developers integrating the library should ensure their build pipelines enforce strict dependency updates to incorporate fixes for heap boundary checks. For organizations unable to immediately update, implementing input sanitization at the application layer before passing data to the image processing engine can provide a temporary buffer against exploitation. This involves validating that rowBytes is mathematically consistent with width and bits-per-pixel values before invoking decoding functions. Additionally, deploying runtime protection mechanisms such as Address Sanitizer during testing phases or utilizing heap hardening features in modern operating systems like Windows Data Execution Prevention combined with structured exception handling can help detect and mitigate the impact of out-of-bounds reads. Regular security audits focusing on image parsing libraries are recommended to identify similar validation gaps across other supported formats within the software ecosystem.