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CVE-2026-54758 is a stack-based buffer overflow vulnerability in Notepad++ affecting builds prior to 8.9.7. The flaw is in the core function expandNppEnvironmentStrs, where a missing bounds check allows data to overflow a fixed-size stack buffer during environment string expansion. This can corrupt adjacent stack memory and trigger memory corruption conditions. Public reporting characterized the issue as theoretically capable of leading to remote code execution, but also noted that compiler-enabled /GS stack canary protection detects the overwrite in practice, making observed exploitation outcomes more consistent with process termination than reliable code execution.
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No public exploit code observed for this vulnerability.
6 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
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.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
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Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.