CVE-2026-44034
Description
A flaw was found in DCMTK. A heap-based out-of-bounds read vulnerability occurs in the frame decoding routine due to missing length validation on image data fragments. By enticing a user or application to process a specially crafted Run-Length Encoded (RLE) DICOM file, an attacker could trigger an out-of-bounds memory read, leading to information disclosure of adjacent heap memory or causing an application crash that results in a Denial of Service (DoS).
Statement
This vulnerability is rated as Moderate impact because exploitation requires a user or application to process an untrusted medical image file, limiting the outcome to bounded heap memory disclosure or a process crash rather than arbitrary code execution. Standard command-line utilities within the package avoid the defective code path, which is primarily exposed to custom applications that perform frame-by-frame RLE decoding. Furthermore, DCMTK is not included in core Red Hat Enterprise Linux releases and is maintained only in community repositories.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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