CVE-2026-4739
Integer Overflow in ITK Expat Module Allows Potential Exploits
Publication date: 2026-03-24
Last updated on: 2026-05-05
Assigner: Government Technology Agency of Singapore Cyber Security Group (GovTech CSG)
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| insightsoftwareconsortium | itk | to 2.7.1 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-190 | The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CVE-2026-4739 is an integer overflow vulnerability found in the Expat XML parser code integrated into the Insight Toolkit (ITK) project, specifically in the file Modules/ThirdParty/Expat/src/expat/xmlparse.c. This vulnerability arises from cloned functions that can cause integer values to overflow or wrap around, potentially leading to incorrect processing of XML data.
The issue is related to a previously reported vulnerability (CVE-2022-22822) in the upstream libexpat library. The ITK project applied a specific security patch to prevent integer overflow at multiple points in the Expat codebase, mitigating risks associated with this vulnerability.
How can this vulnerability impact me? :
This integer overflow vulnerability can lead to incorrect results when processing XML data, which may cause security issues such as memory corruption or unexpected behavior in applications using the ITK library. Exploiting this flaw could potentially allow attackers to manipulate XML parsing, leading to denial of service or other security risks.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
To mitigate the CVE-2026-4739 vulnerability, you should update the Insight Toolkit (ITK) to version 2.7.1 or later, where the integer overflow issue in the Expat XML parser has been patched.
The fix involves applying a specific security patch backported from the upstream libexpat library that prevents integer overflow in the Expat code used by ITK.
Since a full upstream update of the bundled Expat library is complex, the maintainers have applied this targeted patch to address the vulnerability effectively.