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CVE-2026-54758 is a stack-based buffer overflow vulnerability in Notepad++ affecting versions prior to 8.9.7. The flaw resides in the core function expandNppEnvironmentStrs and is caused by insufficient bounds checking when processing environment variable names and copying data into a fixed-size stack-allocated buffer or structure. A crafted input containing unusually long or malformed environment variable references can trigger an out-of-bounds write, resulting in memory corruption within the Notepad++ process. Public reporting describes the issue as potentially leading to remote code execution in theory, although some technical analysis indicates the compiler's /GS stack canary detects the corruption in practical cases, making application termination the more likely observed outcome.
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No public exploit code observed for this vulnerability.
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Stack buffer overflow vulnerability in the expandNppEnvironmentStrs function of Notepad++ caused by insufficient bounds checking when processing environment variable names, leading to memory corruption, denial of service, and possible arbitrary code execution.
A stack buffer overflow vulnerability in Notepad++'s expandNppEnvironmentStrs function that may lead to memory corruption and possible remote code execution.
A stack buffer overflow vulnerability in the Notepad++ expandNppEnvironmentStrs core function that could cause memory corruption and possible remote code execution.
A stack buffer overflow in Notepad++ caused by a missing bounds check in expandNppEnvironmentStrs; the stack canary mitigates practical impact to a crash rather than reliable code execution.
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Cross-references every affected SKU, including bundled OEM variants.
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