CVE-2026-26054 (GCVE-0-2026-26054)

Vulnerability from cvelistv5 – Published: 2026-09-24 16:48 – Updated: 2026-09-24 16:48
VLAI
Title
SumatraPDF: Heap out-of-bounds read in MOBI header parser.
Summary
SumatraPDF is a multi-format reader for Windows. Prior to 3.6, the MobiDoc::ParseHeader function in src/MobiDoc.cpp validates a record using kMobiHeaderMinLen but DecodeMobiDocHeader constructs a decoder sized for kMobiHeaderLen without receiving the actual remaining buffer length. A malformed MOBI file can use an attacker-controlled header length to bypass optional-field early returns and cause the decoder to read beyond a short heap buffer. Opening the crafted document can crash SumatraPDF. This issue is fixed in version 3.6.
Severity
6.8 (Medium)
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
sumatrapdfreader sumatrapdf Affected: < 3.6
guessed Create a notification for this product.
Show details on NVD website
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{
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          "value": "SumatraPDF is a multi-format reader for Windows. Prior to 3.6, the MobiDoc::ParseHeader function in src/MobiDoc.cpp validates a record using kMobiHeaderMinLen but DecodeMobiDocHeader constructs a decoder sized for kMobiHeaderLen without receiving the actual remaining buffer length. A malformed MOBI file can use an attacker-controlled header length to bypass optional-field early returns and cause the decoder to read beyond a short heap buffer. Opening the crafted document can crash SumatraPDF. This issue is fixed in version 3.6."
        }
      ],
      "metrics": [
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            "attackRequirements": "NONE",
            "attackVector": "LOCAL",
            "baseScore": 6.8,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-125",
              "description": "CWE-125: Out-of-bounds Read",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-24T16:48:03.247Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-27p6-wrfp-pgm8",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-27p6-wrfp-pgm8"
        },
        {
          "name": "https://github.com/sumatrapdfreader/sumatrapdf/issues/5318",
          "tags": [
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          "url": "https://github.com/sumatrapdfreader/sumatrapdf/issues/5318"
        },
        {
          "name": "https://github.com/sumatrapdfreader/sumatrapdf/commit/24b9ce83383bbaa48b3efe00e4d30cccea126198",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/sumatrapdfreader/sumatrapdf/commit/24b9ce83383bbaa48b3efe00e4d30cccea126198"
        },
        {
          "name": "https://github.com/sumatrapdfreader/sumatrapdf/releases/tag/3.6rel",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/sumatrapdfreader/sumatrapdf/releases/tag/3.6rel"
        }
      ],
      "source": {
        "advisory": "GHSA-27p6-wrfp-pgm8",
        "discovery": "UNKNOWN"
      },
      "title": "SumatraPDF: Heap out-of-bounds read in MOBI header parser."
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-26054",
    "datePublished": "2026-09-24T16:48:03.247Z",
    "dateReserved": "2026-02-10T18:01:31.899Z",
    "dateUpdated": "2026-09-24T16:48:03.247Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
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      "date": "2026-09-27",
      "epss": "0.00135",
      "percentile": "0.02435"
    },
    "nvd": {
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        "affected": [
          {
            "affectedData": [
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                "product": "sumatrapdf",
                "vendor": "sumatrapdfreader",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 3.6"
                  }
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        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "SumatraPDF is a multi-format reader for Windows. Prior to 3.6, the MobiDoc::ParseHeader function in src/MobiDoc.cpp validates a record using kMobiHeaderMinLen but DecodeMobiDocHeader constructs a decoder sized for kMobiHeaderLen without receiving the actual remaining buffer length. A malformed MOBI file can use an attacker-controlled header length to bypass optional-field early returns and cause the decoder to read beyond a short heap buffer. Opening the crafted document can crash SumatraPDF. This issue is fixed in version 3.6."
          }
        ],
        "id": "CVE-2026-26054",
        "lastModified": "2026-09-24T17:17:04.673",
        "metrics": {
          "cvssMetricV40": [
            {
              "cvssData": {
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                "Recovery": "NOT_DEFINED",
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                "attackRequirements": "NONE",
                "attackVector": "LOCAL",
                "availabilityRequirement": "NOT_DEFINED",
                "baseScore": 6.8,
                "baseSeverity": "MEDIUM",
                "confidentialityRequirement": "NOT_DEFINED",
                "exploitMaturity": "NOT_DEFINED",
                "integrityRequirement": "NOT_DEFINED",
                "modifiedAttackComplexity": "NOT_DEFINED",
                "modifiedAttackRequirements": "NOT_DEFINED",
                "modifiedAttackVector": "NOT_DEFINED",
                "modifiedPrivilegesRequired": "NOT_DEFINED",
                "modifiedSubAvailabilityImpact": "NOT_DEFINED",
                "modifiedSubConfidentialityImpact": "NOT_DEFINED",
                "modifiedSubIntegrityImpact": "NOT_DEFINED",
                "modifiedUserInteraction": "NOT_DEFINED",
                "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
                "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
                "modifiedVulnIntegrityImpact": "NOT_DEFINED",
                "privilegesRequired": "NONE",
                "providerUrgency": "NOT_DEFINED",
                "subAvailabilityImpact": "NONE",
                "subConfidentialityImpact": "NONE",
                "subIntegrityImpact": "NONE",
                "userInteraction": "PASSIVE",
                "valueDensity": "NOT_DEFINED",
                "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
                "version": "4.0",
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                "vulnConfidentialityImpact": "NONE",
                "vulnIntegrityImpact": "NONE",
                "vulnerabilityResponseEffort": "NOT_DEFINED"
              },
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
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        "published": "2026-09-24T17:17:04.553",
        "references": [
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            "url": "https://github.com/sumatrapdfreader/sumatrapdf/commit/24b9ce83383bbaa48b3efe00e4d30cccea126198"
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            "url": "https://github.com/sumatrapdfreader/sumatrapdf/releases/tag/3.6rel"
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        "vulnStatus": "Deferred",
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            "type": "Primary"
          }
        ]
      }
    }
  }
}



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