FKIE_CVE-2026-55894

Vulnerability from fkie_nvd - Published: 2026-08-20 22:17 - Updated: 2026-08-21 15:16
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
Summary
Capstone is a disassembly framework. In 6.0.0-Alpha9 and earlier, Capstone's arch/SH/SHDisassembler.c sh_disassemble() function computes an idx value from a raw 16-bit instruction without ensuring it is within the active mode-specific decode[] function-pointer table. An application using CS_ARCH_SH with CS_MODE_SH2A or CS_MODE_SH4A and CS_MODE_SHFPU can pass crafted bytecode through cs_disasm_iter() or cs_disasm(), causing the decode[idx] test to read outside the table and terminate the process with a segmentation fault. No code execution or information disclosure was demonstrated. This issue is fixed in version 6.0.0-Alpha10.
References
security-advisories@github.comhttps://github.com/capstone-engine/capstone/commit/09e76802380b9e94d9720c44458d9d5282219e7e
security-advisories@github.comhttps://github.com/capstone-engine/capstone/commit/e17ee44a8307ea33375b4727ac4f987650bf7bed
security-advisories@github.comhttps://github.com/capstone-engine/capstone/pull/2968
security-advisories@github.comhttps://github.com/capstone-engine/capstone/pull/2969
security-advisories@github.comhttps://github.com/capstone-engine/capstone/releases/tag/6.0.0-Alpha10
security-advisories@github.comhttps://github.com/capstone-engine/capstone/security/advisories/GHSA-gf2c-xwcp-hvf4
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/capstone-engine/capstone/security/advisories/GHSA-gf2c-xwcp-hvf4
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "capstone",
          "vendor": "capstone-engine",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 6.0.0-Alpha10"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Capstone is a disassembly framework. In 6.0.0-Alpha9 and earlier, Capstone\u0027s arch/SH/SHDisassembler.c sh_disassemble() function computes an idx value from a raw 16-bit instruction without ensuring it is within the active mode-specific decode[] function-pointer table. An application using CS_ARCH_SH with CS_MODE_SH2A or CS_MODE_SH4A and CS_MODE_SHFPU can pass crafted bytecode through cs_disasm_iter() or cs_disasm(), causing the decode[idx] test to read outside the table and terminate the process with a segmentation fault. No code execution or information disclosure was demonstrated. This issue is fixed in version 6.0.0-Alpha10."
    }
  ],
  "id": "CVE-2026-55894",
  "lastModified": "2026-08-21T15:16:42.140",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "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",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-55894",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-21T14:59:57.566989Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-20T22:17:22.930",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/capstone-engine/capstone/commit/09e76802380b9e94d9720c44458d9d5282219e7e"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/capstone-engine/capstone/commit/e17ee44a8307ea33375b4727ac4f987650bf7bed"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/capstone-engine/capstone/pull/2968"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/capstone-engine/capstone/pull/2969"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/capstone-engine/capstone/releases/tag/6.0.0-Alpha10"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/capstone-engine/capstone/security/advisories/GHSA-gf2c-xwcp-hvf4"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/capstone-engine/capstone/security/advisories/GHSA-gf2c-xwcp-hvf4"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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