Search

Find a vulnerability

Search criteria

    1 vulnerability by any1

    CVE-2026-42859 (GCVE-0-2026-42859)

    Vulnerability from cvelistv5 – Published: 2026-05-11 17:36 – Updated: 2026-05-11 18:22
    VLAI
    Title
    Neat VNC: Buffer overflow due to oversized RSA public keys
    Summary
    Neat VNC is a VNC server library. Prior to 0.9.6, a pre-authentication stack buffer overflow exists in neatvnc in the RSA-AES security type handler. An unauthenticated remote attacker who can reach the VNC listening socket can send a crafted security type 5 (RSA-AES) or security type 129 (RSA-AES-256) handshake with an oversized client RSA public key, causing rsa_aes_send_challenge in src/auth/rsa-aes.c to overflow a 1024-byte on-stack buffer when encrypting the server challenge. This results in at least a denial of service via server crash. This vulnerability is fixed in 0.9.6.
    Severity
    8.1 (High)
    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U
    SSVC
    Exploitation: none Automatable: yes Technical Impact: total
    CISA Coordinator · CISA-ADP (v2.0.3)
    Decision recorded 2026-05-11 18:21 UTC
    CWE
    • CWE-120 - Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
    Assigner
    GitHub_M CNA
    References
    Impacted products
    Vendor Product Version
    any1 neatvnc Affected: < 0.9.6
    		Create a notification for this product.
    Show details on NVD website
    To clipboard 

    {
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-42859",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-11T18:21:36.453865Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-11T18:22:03.144Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "neatvnc",
          "vendor": "any1",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.9.6"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Neat VNC is a VNC server library. Prior to 0.9.6, a pre-authentication stack buffer overflow exists in neatvnc in the RSA-AES security type handler. An unauthenticated remote attacker who can reach the VNC listening socket can send a crafted security type 5 (RSA-AES) or security type 129 (RSA-AES-256) handshake with an oversized client RSA public key, causing rsa_aes_send_challenge in src/auth/rsa-aes.c to overflow a 1024-byte on-stack buffer when encrypting the server challenge. This results in at least a denial of service via server crash. This vulnerability is fixed in 0.9.6."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-120",
              "description": "CWE-120: Buffer Copy without Checking Size of Input (\u0027Classic Buffer Overflow\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T17:36:08.143Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/any1/neatvnc/security/advisories/GHSA-567c-gpv8-qh9h",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/any1/neatvnc/security/advisories/GHSA-567c-gpv8-qh9h"
        },
        {
          "name": "https://github.com/any1/neatvnc/commit/1f6cd6b75cc167fed3a19a9d1552a1f662f6b337",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/any1/neatvnc/commit/1f6cd6b75cc167fed3a19a9d1552a1f662f6b337"
        }
      ],
      "source": {
        "advisory": "GHSA-567c-gpv8-qh9h",
        "discovery": "UNKNOWN"
      },
      "title": "Neat VNC: Buffer overflow due to oversized RSA public keys"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-42859",
    "datePublished": "2026-05-11T17:36:08.143Z",
    "dateReserved": "2026-04-30T16:44:48.379Z",
    "dateUpdated": "2026-05-11T18:22:03.144Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}