FKIE_CVE-2026-23533

Vulnerability from fkie_nvd - Published: 2026-01-19 18:16 - Updated: 2026-06-30 03:17
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.6 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
Summary
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the RDPGFX ClearCodec decode path when maliciously crafted residual data causes out-of-bounds writes during color output. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.
References
security-advisories@github.comhttps://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L268-L281Product
security-advisories@github.comhttps://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L336Product
security-advisories@github.comhttps://github.com/FreeRDP/FreeRDP/releases/tag/3.21.0Release Notes
security-advisories@github.comhttps://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-32q9-m5qr-9j2vExploit, Vendor Advisory
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:2048
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:2081
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:2222
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:2714
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:2736
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:2770
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:2824
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:2952
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:3036
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:3037
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:3038
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:3039
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:3041
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/security/cve/CVE-2026-23533
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://bugzilla.redhat.com/show_bug.cgi?id=2430886
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23533.json
Impacted products
Vendor Product Version
freerdp freerdp *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "FreeRDP",
          "vendor": "FreeRDP",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 3.21.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    },
    {
      "affectedData": [
        {
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            "cpe:/o:redhat:rhel_els:7"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux Server (v. 7 ELS)",
          "vendor": "Red Hat"
        },
        {
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            "cpe:/o:redhat:rhel_els:7"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux Server Optional (v. 7 ELS)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux_eus:10.0"
          ],
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          "product": "Red Hat Enterprise Linux AppStream EUS (v. 10.0)",
          "vendor": "Red Hat"
        },
        {
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          ],
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          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:enterprise_linux:8::appstream"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux AppStream (v. 8)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_aus:8.2::appstream"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux AppStream AUS (v. 8.2)",
          "vendor": "Red Hat"
        },
        {
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          ],
          "defaultStatus": "affected",
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          "vendor": "Red Hat"
        },
        {
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          ],
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          "product": "Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)",
          "vendor": "Red Hat"
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          "defaultStatus": "affected",
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          "vendor": "Red Hat"
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        {
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          "defaultStatus": "affected",
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          "vendor": "Red Hat"
        },
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        },
        {
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          "vendor": "Red Hat"
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        {
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          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
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          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux CRB (v. 8)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
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          ],
          "defaultStatus": "affected",
          "product": "Red Hat CodeReady Linux Builder EUS (v.9.4)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
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          "product": "Red Hat CodeReady Linux Builder EUS (v.9.6)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
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          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
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          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux 6",
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        }
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
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              "criteria": "cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "E6899265-905F-4A3A-96D3-07B552FBFBEC",
              "versionEndExcluding": "3.21.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
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      ]
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the RDPGFX ClearCodec decode path when maliciously crafted residual data causes out-of-bounds writes during color output. A malicious server can trigger a client\u2011side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code\u2011execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue."
    },
    {
      "lang": "es",
      "value": "FreeRDP es una implementaci\u00f3n gratuita del Protocolo de Escritorio Remoto. Antes de la versi\u00f3n 3.21.0, se produce un desbordamiento de b\u00fafer de mont\u00f3n del lado del cliente en la ruta de decodificaci\u00f3n RDPGFX ClearCodec cuando datos residuales creados maliciosamente causan escrituras fuera de l\u00edmites durante la salida de color. Un servidor malicioso puede desencadenar un desbordamiento de b\u00fafer de mont\u00f3n del lado del cliente, causando un fallo (DoS) y una posible corrupci\u00f3n del mont\u00f3n con riesgo de ejecuci\u00f3n de c\u00f3digo dependiendo del comportamiento del asignador y del dise\u00f1o del mont\u00f3n circundante. La versi\u00f3n 3.21.0 contiene un parche para el problema."
    }
  ],
  "id": "CVE-2026-23533",
  "lastModified": "2026-06-30T03:17:32.550",
  "metrics": {
    "cvssMetricV31": [
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        "cvssData": {
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          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
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        "source": "nvd@nist.gov",
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          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H",
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          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
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          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "PROOF_OF_CONCEPT",
          "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:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/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",
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          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
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          "role": "CISA Coordinator",
          "timestamp": "2026-01-20T21:38:13.072739Z",
          "version": "2.0.3"
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  "published": "2026-01-19T18:16:05.170",
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      "tags": [
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  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
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          "value": "CWE-122"
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      "source": "security-advisories@github.com",
      "type": "Primary"
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      "type": "Secondary"
    }
  ]
}


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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.
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  • 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.