CWE-1046: Creation of Immutable Text Using String Concatenation
The product creates an immutable text string using string concatenation operations.
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Overview
When building a string via a looping feature (e.g., a FOR or WHILE loop), the use of += to append to the existing string will result in the creation of a new object with each iteration, which can be inefficient in comparison with use of text buffer data elements.
Real-world CVEs
1 recorded CVEs are caused by CWE-1046 (Creation of Immutable Text Using String Concatenation). The highest-severity and most recent are shown first. 1 new CWE-1046 CVE has been recorded so far in 2026.
Common consequences
What can happen when CWE-1046 is exploited.
Reduce Performance
Affects: Other
This issue can make the product perform more slowly. If the relevant code is reachable by an attacker, then this could be influenced to create performance problem.
How it happens
When it is introduced
Typically introduced during these phases of the software lifecycle.