{"id":"CVE-2026-86054","summary":"Notepad++: Stack Buffer Overflow in `NppParameters::writeSession` via overlong session path","details":"Notepad++ is a free and open-source source code editor. Prior to 8.9.8, Notepad++ contains a stack buffer overflow in NppParameters::writeSession in PowerEditor/src/Parameters.cpp because it copies a session path derived from -settingsDir= into backupPathName[MAX_PATH] with unbounded wcscpy and appends SESSION_BACKUP_EXT with unbounded wcscat. A sufficiently long settings directory causes the backup suffix to exceed the fixed stack buffer when Notepad++ saves the session, and the protected release build terminates through its stack canary, causing denial of service. This issue is fixed in version 8.9.8.","aliases":["GHSA-pxgg-96p2-c3hx"],"modified":"2026-09-25T08:24:15.336726Z","published":"2026-09-22T17:12:38.351Z","database_specific":{"cwe_ids":["CWE-121"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86054.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8"},{"type":"WEB","url":"https://notepad-plus-plus.org/news/v898-released"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86054.json"},{"type":"ADVISORY","url":"https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-pxgg-96p2-c3hx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86054"},{"type":"FIX","url":"https://github.com/notepad-plus-plus/notepad-plus-plus/commit/046af3f626be7715886412313fc18f58b30dfcaf"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/notepad-plus-plus/notepad-plus-plus","events":[{"introduced":"0"},{"fixed":"046af3f626be7715886412313fc18f58b30dfcaf"},{"fixed":"40f896e6f6c49a29b6ca3f559696dd786f40152d"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"8.9.8"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v8.9.7","v8.9.6.4","v8.9.6.2","v8.9.6.1","v8.9.6","v8.9.5","v8.9.4","v8.9.3","v8.9.2","v8.9.1","v8.9","v8.8.9","v8.8.8","v8.8.7","v8.8.6","v8.8.5","v8.8.4","v8.8.3","v8.8.2","v8.8.1","v8.8","v8.7.9","v8.7.8","v8.7.7","v8.7.6","v8.7.5","v8.7.4","v8.7.3","v8.7.2","v8.7.1","v8.7","v8.6.9","v8.6.8","v8.6.7","v8.6.6","v8.6.5","v8.6.4","v8.6.3","v8.6.2","v8.6.1","v8.6","v8.5.8","v8.5.7","v8.5.6","v8.5.5","v8.5.4","v8.5.3","v8.5.2","v8.5.1","v8.5","v8.4.9","v8.4.8","v8.4.7","v8.4.6","v8.4.5","v8.4.4","v8.4.3","v8.4.2","v8.4.1","v8.4","v8.3.3","v8.3.2","v8.3.1","v8.3","v8.2.1","v8.2","v8.1.9.3","v8.1.9.2","v8.1.9.1","v8.1.9","v8.1.8","v8.1.7","v8.1.6","v8.1.5","v8.1.4","v8.1.3","v8.1.2","v8.1.1","v8.1","v8","v7.9.5","v7.9.4","v7.9.3","v7.9.2","v7.9.1","v7.9","v7.8.9","v7.8.8","v7.8.7","v7.8.6","v7.8.5","v7.8.4","v7.8.3","v7.8.2","v7.8.1","v7.8","v7.7.1","v7.7","v7.6.6","v7.6.5","v7.6.4","v7.6.3","v7.6.2","v7.6.1","v7.6","v7.5.9","v7.5.8","v7.5.7","v7.5.6","v7.5.5","v7.5.4","v7.5.3","v7.5.2","v7.5.1","v7.4.2","v7.4.1","v7.4","v7.3.3","v7.3.2","v7.3.1","7.3.1","v7.3","v7.2.2","7.2.2","v7.2.1","v7.2","v7.1","v7","v6.9.2","v6.9.1","v6.9","v6.8.9","v6.8.8","v6.8.7","v6.8.6","v6.8.5","v6.8.4","v6.8.3","v6.8.2","v6.8.1","v6.8","v6.7.9.2","v6.7.9.1","v6.7.9","v6.7.8.2","v6.7.8.1","v6.7.8","v6.7.7","v6.7.5","v6.7.4_-_Je_suis_Charlie_edition","v6.7.3","v6.7.2","v6.7.1","v6.7","v6.6.9","v6.6.8","v6.6.7","v6.6.6_-_Friday_the_13th_edition","v6.6.4","v6.6.3","v6.6.2","v6.6.1","v6.6","v6.5.5","v6.5.4","v6.5.3","v6.5.2","v6.5.1","v6.5","v6.4.5","v6.4.4","v6.4.3","v6.4.2","v6.4.1","v6.4","v6.3.3","v6.3.2","v6.3.1","v6.3","v6.2.3_-_End_of_World_Edition","v6.2.2","v6.2.1","v6.2","v6.1.8","v6.1.7","v6.1.6","v6.1.5","v6.1.4","v6.1.3","v6.1.2","v6.1.1","v6.1","v6","v5.9.8","v5.9.7","v5.9.6.2","v5.9.6.1","v5.9.6","v5.9.5","v5.9.4","v5.9.3","v5.9.2","v5.9.1","v5.9","v5.8.7","v5.8.6","v5.8.5","v5.8.4","v5.8.3","v5.8.2","v5.8.1","v5.8","v5.7","v5.6.8","v5.6.7","v5.6.6","v5.6.5","v5.6.4","v5.6.3","v5.6.2","v5.6.1","v5.6","v5.5.1","v5.5","v5.4.5","v5.4.4","v5.4.3","v5.4.2"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-86054.json","vanir_signatures_modified":"2026-09-25T08:24:15Z","vanir_signatures":[{"digest":{"line_hashes":["169247741825144624397136188255710522833","50731968414209058442502004713777493169","67552166248832970620335487999155388133","180244811389147017096989761483559355784","65253073140970142388915739552492156679","151027174967116092706683563360107255966","70225067072857101676133997820036074314","255049643374874331213349666144399461309","38136074712481667624842709037354577511","328958860471478512977853027603915372828","16288141341316623331258927018528679518","223564522032782241237306493797029526086","76914679914538767800483762583720520844","112169958922795484295213951280942393151","91074491918983620300922947778724979227","333977570440272383146501816484296782007","332107971182812462561610019347429323686","158865921636288670345205618624457417954"],"threshold":0.9},"id":"CVE-2026-86054-38f51f42","signature_type":"Line","signature_version":"v1","source":"https://github.com/notepad-plus-plus/notepad-plus-plus/commit/046af3f626be7715886412313fc18f58b30dfcaf","target":{"file":"PowerEditor/src/Parameters.cpp"},"deprecated":false},{"deprecated":false,"digest":{"function_hash":"296510864734399106219181515366821524363","length":5776},"id":"CVE-2026-86054-99c089ca","signature_type":"Function","signature_version":"v1","source":"https://github.com/notepad-plus-plus/notepad-plus-plus/commit/046af3f626be7715886412313fc18f58b30dfcaf","target":{"file":"PowerEditor/src/Parameters.cpp","function":"NppParameters::writeSession"}}]}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"}]}