CVE-2026-86054 (GCVE-0-2026-86054)

Vulnerability from cvelistv5 – Published: 2026-09-22 17:12 – Updated: 2026-09-22 17:12
VLAI
Title
Notepad++: Stack Buffer Overflow in `NppParameters::writeSession` via overlong session path
Summary
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.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE
  • CWE-121 - Stack-based Buffer Overflow
Assigner
References
Impacted products
Vendor Product Version CPE status
notepad-plus-plus notepad-plus-plus Affected: < 8.9.8
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          "vendor": "notepad-plus-plus",
          "versions": [
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          "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."
        }
      ],
      "metrics": [
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          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
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              "description": "CWE-121: Stack-based Buffer Overflow",
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              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-22T17:12:38.351Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "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/security/advisories/GHSA-pxgg-96p2-c3hx"
        },
        {
          "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/commit/046af3f626be7715886412313fc18f58b30dfcaf"
        },
        {
          "name": "https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8",
          "tags": [
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          ],
          "url": "https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8"
        },
        {
          "name": "https://notepad-plus-plus.org/news/v898-released",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://notepad-plus-plus.org/news/v898-released"
        }
      ],
      "source": {
        "advisory": "GHSA-pxgg-96p2-c3hx",
        "discovery": "UNKNOWN"
      },
      "title": "Notepad++: Stack Buffer Overflow in `NppParameters::writeSession` via overlong session path"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-86054",
    "datePublished": "2026-09-22T17:12:38.351Z",
    "dateReserved": "2026-09-04T19:29:21.059Z",
    "dateUpdated": "2026-09-22T17:12:38.351Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
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      "date": "2026-09-23",
      "epss": "0.00202",
      "percentile": "0.10367"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
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              {
                "product": "notepad-plus-plus",
                "vendor": "notepad-plus-plus",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 8.9.8"
                  }
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        ],
        "cveTags": [],
        "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."
          }
        ],
        "id": "CVE-2026-86054",
        "lastModified": "2026-09-23T18:28:25.093",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
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                "confidentialityImpact": "HIGH",
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                "userInteraction": "REQUIRED",
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              "impactScore": 5.9,
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            }
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        "published": "2026-09-22T18:17:23.827",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/notepad-plus-plus/notepad-plus-plus/commit/046af3f626be7715886412313fc18f58b30dfcaf"
          },
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            "source": "security-advisories@github.com",
            "url": "https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8"
          },
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            "source": "security-advisories@github.com",
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          {
            "source": "security-advisories@github.com",
            "url": "https://notepad-plus-plus.org/news/v898-released"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Awaiting Analysis",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-121"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.