Vulnerability-Lookup

FKIE_CVE-2026-32854

Vulnerability from fkie_nvd - Published: 2026-03-24 18:16 - Updated: 2026-03-25 21:57

Severity

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

LibVNCServer versions 0.9.15 and prior (fixed in commit dc78dee) contain null pointer dereference vulnerabilities in the HTTP proxy handlers within httpProcessInput() in httpd.c that allow remote attackers to cause a denial of service by sending specially crafted HTTP requests. Attackers can exploit missing validation of strchr() return values in the CONNECT and GET proxy handling paths to trigger null pointer dereferences and crash the server when httpd and proxy features are enabled.

References

URL	Tags
disclosure@vulncheck.com	https://github.com/LibVNC/libvncserver/commit/dc78dee51a7e270e537a541a17befdf2073f5314	Patch
disclosure@vulncheck.com	https://github.com/LibVNC/libvncserver/security/advisories/GHSA-xjp8-4qqv-5x4x	Exploit, Vendor Advisory
disclosure@vulncheck.com	https://www.vulncheck.com/advisories/libvncserver-httpd-proxy-null-pointer-dereference	Third Party Advisory

Impacted products

	Vendor	Product	Version
	libvncserver_project	libvncserver	*

JSON

To clipboard

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:libvncserver_project:libvncserver:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "A73C0099-80A6-4B55-8B34-7968BFADE90A",
              "versionEndExcluding": "0.9.15",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "LibVNCServer versions 0.9.15 and prior (fixed in\u00a0commit dc78dee) contain null pointer dereference vulnerabilities in the HTTP proxy handlers within httpProcessInput() in httpd.c that allow remote attackers to cause a denial of service by sending specially crafted HTTP requests. Attackers can exploit missing validation of strchr() return values in the CONNECT and GET proxy handling paths to trigger null pointer dereferences and crash the server when httpd and proxy features are enabled."
    },
    {
      "lang": "es",
      "value": "Las versiones 0.9.15 y anteriores de LibVNCServer (corregido en el commit dc78dee) contienen vulnerabilidades de desreferencia de puntero nulo en los manejadores de proxy HTTP dentro de httpProcessInput() en httpd.c que permiten a atacantes remotos causar una denegaci\u00f3n de servicio enviando solicitudes HTTP especialmente dise\u00f1adas. Los atacantes pueden explotar la falta de validaci\u00f3n de los valores de retorno de strchr() en las rutas de manejo de proxy CONNECT y GET para desencadenar desreferencias de puntero nulo y bloquear el servidor cuando las caracter\u00edsticas httpd y de proxy est\u00e1n habilitadas."
    }
  ],
  "id": "CVE-2026-32854",
  "lastModified": "2026-03-25T21:57:20.137",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.3,
          "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": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/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": "LOW",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-03-24T18:16:09.423",
  "references": [
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/LibVNC/libvncserver/commit/dc78dee51a7e270e537a541a17befdf2073f5314"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "url": "https://github.com/LibVNC/libvncserver/security/advisories/GHSA-xjp8-4qqv-5x4x"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://www.vulncheck.com/advisories/libvncserver-httpd-proxy-null-pointer-dereference"
    }
  ],
  "sourceIdentifier": "disclosure@vulncheck.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ],
      "source": "disclosure@vulncheck.com",
      "type": "Primary"
    }
  ]
}

CVE-2026-32854 (GCVE-0-2026-32854)

Vulnerability from cvelistv5 – Published: 2026-03-24 17:31 – Updated: 2026-03-27 03:52

Title

LibVNCServer httpd proxy NULL Pointer Dereference

Summary

Severity

6.3 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CWE

CWE-476 - NULL pointer dereference

Assigner

VulnCheck

References

3 references

URL	Tags
https://github.com/LibVNC/libvncserver/security/a…	vendor-advisory
https://github.com/LibVNC/libvncserver/commit/dc7…	patch
https://www.vulncheck.com/advisories/libvncserver…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
LibVNC	LibVNCServer	Affected: 0 , ≤ 0.9.15 (semver) Unaffected: dc78dee51a7e270e537a541a17befdf2073f5314 (git)

Credits

Kazuma Matsumoto, a security researcher at GMO Cybersecurity by IERAE, Inc.

Show details on NVD website

JSON

To clipboard

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                "id": "CVE-2026-32854",
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                  },
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                "role": "CISA Coordinator",
                "timestamp": "2026-03-27T03:52:09.338985Z",
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Sightings

Author	Source	Type	Date	Other

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.

Detection rules are retrieved from Rulezet.

Action not permitted

FKIE_CVE-2026-32854

CVE-2026-32854 (GCVE-0-2026-32854)

Tags

Sightings

Nomenclature