FKIE_CVE-2026-21434

Vulnerability from fkie_nvd - Published: 2026-02-12 19:15 - Updated: 2026-06-17 10:18
Severity
5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
webtransport-go is an implementation of the WebTransport protocol. From 0.3.0 to 0.9.0, an attacker can cause excessive memory consumption in webtransport-go's session implementation by sending a WT_CLOSE_SESSION capsule containing an excessively large Application Error Message. The implementation does not enforce the draft-mandated limit of 1024 bytes on this field, allowing a peer to send an arbitrarily large message payload that is fully read and stored in memory. This allows an attacker to consume an arbitrary amount of memory. The attacker must transmit the full payload to achieve the memory consumption, but the lack of any upper bound makes large-scale attacks feasible given sufficient bandwidth. This vulnerability is fixed in 0.10.0.
References
security-advisories@github.comhttps://github.com/quic-go/webtransport-go/releases/tag/v0.10.0Product, Release Notes
security-advisories@github.comhttps://github.com/quic-go/webtransport-go/security/advisories/GHSA-g6x7-jq8p-6q9qVendor Advisory
Impacted products
Vendor Product Version
quic-go webtransport-go *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "webtransport-go",
          "vendor": "quic-go",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.10.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:quic-go:webtransport-go:*:*:*:*:*:go:*:*",
              "matchCriteriaId": "655FC296-1611-47D3-A71F-E5C093D2F463",
              "versionEndExcluding": "0.10.0",
              "versionStartIncluding": "0.3.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "webtransport-go is an implementation of the WebTransport protocol. From 0.3.0 to 0.9.0, an attacker can cause excessive memory consumption in webtransport-go\u0027s session implementation by sending a WT_CLOSE_SESSION capsule containing an excessively large Application Error Message. The implementation does not enforce the draft-mandated limit of 1024 bytes on this field, allowing a peer to send an arbitrarily large message payload that is fully read and stored in memory. This allows an attacker to consume an arbitrary amount of memory. The attacker must transmit the full payload to achieve the memory consumption, but the lack of any upper bound makes large-scale attacks feasible given sufficient bandwidth. This vulnerability is fixed in 0.10.0."
    },
    {
      "lang": "es",
      "value": "webtransport-go es una implementaci\u00f3n del protocolo WebTransport. Desde 0.3.0 hasta 0.9.0, un atacante puede causar un consumo excesivo de memoria en la implementaci\u00f3n de sesi\u00f3n de webtransport-go al enviar una c\u00e1psula WT_CLOSE_SESSION que contiene un Mensaje de Error de Aplicaci\u00f3n excesivamente grande. La implementaci\u00f3n no aplica el l\u00edmite de 1024 bytes exigido por el borrador en este campo, lo que permite a un par enviar una carga \u00fatil de mensaje arbitrariamente grande que se lee y almacena completamente en memoria. Esto permite a un atacante consumir una cantidad arbitraria de memoria. El atacante debe transmitir la carga \u00fatil completa para lograr el consumo de memoria, pero la falta de cualquier l\u00edmite superior hace que los ataques a gran escala sean factibles dado un ancho de banda suficiente. Esta vulnerabilidad est\u00e1 corregida en 0.10.0."
    }
  ],
  "id": "CVE-2026-21434",
  "lastModified": "2026-06-17T10:18:39.907",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "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:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "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"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-21434",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-02-12T18:45:50.348094Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-02-12T19:15:51.333",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Product",
        "Release Notes"
      ],
      "url": "https://github.com/quic-go/webtransport-go/releases/tag/v0.10.0"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://github.com/quic-go/webtransport-go/security/advisories/GHSA-g6x7-jq8p-6q9q"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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