{"id":"CVE-2026-86054","state":"PUBLISHED","title":"Notepad++: Stack Buffer Overflow in `NppParameters::writeSession` via overlong session path","description":"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.","publishedAt":"2026-09-22T17:12:38.351Z","updatedAt":"2026-09-28T17:36:02.778Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["notepad-plus-plus notepad-plus-plus"],"affected":[{"vendor":"notepad-plus-plus","product":"notepad-plus-plus","versions":[{"version":"< 8.9.8","status":"affected"}]}],"references":["https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-pxgg-96p2-c3hx","https://github.com/notepad-plus-plus/notepad-plus-plus/commit/046af3f626be7715886412313fc18f58b30dfcaf","https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8","https://notepad-plus-plus.org/news/v898-released"],"weaknesses":["CWE-121"],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/86xxx/CVE-2026-86054.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-86054","state":"PUBLISHED","datePublished":"2026-09-22T17:12:38.351Z","dateUpdated":"2026-09-28T17:36:02.778Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-04T19:29:21.059Z"},"containers":{"cna":{"title":"Notepad++: Stack Buffer Overflow in `NppParameters::writeSession` via overlong session path","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"notepad-plus-plus","product":"notepad-plus-plus","versions":[{"version":"< 8.9.8","status":"affected"}]}],"references":[{"url":"https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-pxgg-96p2-c3hx","name":"https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-pxgg-96p2-c3hx","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/notepad-plus-plus/notepad-plus-plus/commit/046af3f626be7715886412313fc18f58b30dfcaf","name":"https://github.com/notepad-plus-plus/notepad-plus-plus/commit/046af3f626be7715886412313fc18f58b30dfcaf","tags":["x_refsource_MISC"]},{"url":"https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8","name":"https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8","tags":["x_refsource_MISC"]},{"url":"https://notepad-plus-plus.org/news/v898-released","name":"https://notepad-plus-plus.org/news/v898-released","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":7.8,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-121","lang":"en","description":"CWE-121: Stack-based Buffer Overflow","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-22T17:12:38.351Z"},"source":{"advisory":"GHSA-pxgg-96p2-c3hx","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-pxgg-96p2-c3hx","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-28T17:35:55.930197Z","id":"CVE-2026-86054","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-28T17:36:02.778Z"}}]}}}