CVE-2026-15711 (GCVE-0-2026-15711)

Vulnerability from cvelistv5 – Published: 2026-07-14 19:45 – Updated: 2026-07-15 14:11
VLAI
Title
Libsoup: soupwebsocketconnection: libsoup: websocket remote denial of service via oversized control frame protocol violation
Summary
A vulnerability was found in libsoup's WebSocket frame parsing implementation. The library fails to validate length rules specified in RFC 6455 §5.5, which mandates that all WebSocket control frames (e.g., PING, PONG, CLOSE) contain a payload of 125 bytes or less. A remote, unauthenticated attacker can exploit this by sending a non-compliant, oversized control frame. Because the parser handles this protocol violation improperly instead of throwing an immediate connection termination error, it triggers a internal processing crash, resulting in a remote denial of service (DoS) for applications utilizing libsoup WebSockets.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
Impacted products
Date Public
2026-07-14 09:52
Credits
Red Hat would like to thank Sebastián Alba Vives (@Sebasteuo / 0xS4bb1) for reporting this issue.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-15711",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-15T14:10:43.407984Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-15T14:11:08.927Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://gitlab.gnome.org/GNOME/libsoup/-/issues/515"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:10"
          ],
          "defaultStatus": "affected",
          "packageName": "libsoup3",
          "product": "Red Hat Enterprise Linux 10",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:6"
          ],
          "defaultStatus": "unknown",
          "packageName": "libsoup",
          "product": "Red Hat Enterprise Linux 6",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:7"
          ],
          "defaultStatus": "unknown",
          "packageName": "libsoup",
          "product": "Red Hat Enterprise Linux 7",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:8"
          ],
          "defaultStatus": "affected",
          "packageName": "libsoup",
          "product": "Red Hat Enterprise Linux 8",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:9"
          ],
          "defaultStatus": "affected",
          "packageName": "libsoup",
          "product": "Red Hat Enterprise Linux 9",
          "vendor": "Red Hat"
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Red Hat would like to thank Sebasti\u00e1n Alba Vives (@Sebasteuo / 0xS4bb1) for reporting this issue."
        }
      ],
      "datePublic": "2026-07-14T09:52:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "A vulnerability was found in libsoup\u0027s WebSocket frame parsing implementation. The library fails to validate length rules specified in RFC 6455 \u00a75.5, which mandates that all WebSocket control frames (e.g., PING, PONG, CLOSE) contain a payload of 125 bytes or less. A remote, unauthenticated attacker can exploit this by sending a non-compliant, oversized control frame. Because the parser handles this protocol violation improperly instead of throwing an immediate connection termination error, it triggers a internal processing crash, resulting in a remote denial of service (DoS) for applications utilizing libsoup WebSockets."
        }
      ],
      "metrics": [
        {
          "other": {
            "content": {
              "namespace": "https://access.redhat.com/security/updates/classification/",
              "value": "Moderate"
            },
            "type": "Red Hat severity rating"
          }
        },
        {
          "cvssV3_1": {
            "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"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-14T19:45:47.784Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "tags": [
            "vdb-entry",
            "x_refsource_REDHAT"
          ],
          "url": "https://access.redhat.com/security/cve/CVE-2026-15711"
        },
        {
          "name": "RHBZ#2499924",
          "tags": [
            "issue-tracking",
            "x_refsource_REDHAT"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2499924"
        },
        {
          "url": "https://gitlab.gnome.org/GNOME/libsoup/-/issues/515"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-07-14T09:46:13.021Z",
          "value": "Reported to Red Hat."
        },
        {
          "lang": "en",
          "time": "2026-07-14T09:52:00.000Z",
          "value": "Made public."
        }
      ],
      "title": "Libsoup: soupwebsocketconnection: libsoup: websocket remote denial of service via oversized control frame protocol violation",
      "workarounds": [
        {
          "lang": "en",
          "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."
        }
      ],
      "x_generator": {
        "engine": "cvelib 1.8.0"
      },
      "x_redhatCweChain": "CWE-770: Allocation of Resources Without Limits or Throttling"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2026-15711",
    "datePublished": "2026-07-14T19:45:47.784Z",
    "dateReserved": "2026-07-14T09:45:31.488Z",
    "dateUpdated": "2026-07-15T14:11:08.927Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-15711",
      "date": "2026-07-15",
      "epss": "0.00431",
      "percentile": "0.34853"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-15711\",\"sourceIdentifier\":\"secalert@redhat.com\",\"published\":\"2026-07-14T20:16:57.177\",\"lastModified\":\"2026-07-15T18:20:21.237\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A vulnerability was found in libsoup\u0027s WebSocket frame parsing implementation. The library fails to validate length rules specified in RFC 6455 \u00a75.5, which mandates that all WebSocket control frames (e.g., PING, PONG, CLOSE) contain a payload of 125 bytes or less. A remote, unauthenticated attacker can exploit this by sending a non-compliant, oversized control frame. Because the parser handles this protocol violation improperly instead of throwing an immediate connection termination error, it triggers a internal processing crash, resulting in a remote denial of service (DoS) for applications utilizing libsoup WebSockets.\"}],\"affected\":[{\"source\":\"secalert@redhat.com\",\"affectedData\":[{\"vendor\":\"Red Hat\",\"product\":\"Red Hat Enterprise Linux 10\",\"defaultStatus\":\"affected\",\"collectionURL\":\"https://access.redhat.com/downloads/content/package-browser/\",\"packageName\":\"libsoup3\",\"cpes\":[\"cpe:/o:redhat:enterprise_linux:10\"]},{\"vendor\":\"Red Hat\",\"product\":\"Red Hat Enterprise Linux 6\",\"defaultStatus\":\"unknown\",\"collectionURL\":\"https://access.redhat.com/downloads/content/package-browser/\",\"packageName\":\"libsoup\",\"cpes\":[\"cpe:/o:redhat:enterprise_linux:6\"]},{\"vendor\":\"Red Hat\",\"product\":\"Red Hat Enterprise Linux 7\",\"defaultStatus\":\"unknown\",\"collectionURL\":\"https://access.redhat.com/downloads/content/package-browser/\",\"packageName\":\"libsoup\",\"cpes\":[\"cpe:/o:redhat:enterprise_linux:7\"]},{\"vendor\":\"Red Hat\",\"product\":\"Red Hat Enterprise Linux 8\",\"defaultStatus\":\"affected\",\"collectionURL\":\"https://access.redhat.com/downloads/content/package-browser/\",\"packageName\":\"libsoup\",\"cpes\":[\"cpe:/o:redhat:enterprise_linux:8\"]},{\"vendor\":\"Red Hat\",\"product\":\"Red Hat Enterprise Linux 9\",\"defaultStatus\":\"affected\",\"collectionURL\":\"https://access.redhat.com/downloads/content/package-browser/\",\"packageName\":\"libsoup\",\"cpes\":[\"cpe:/o:redhat:enterprise_linux:9\"]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"secalert@redhat.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-07-15T14:10:43.407984Z\",\"id\":\"CVE-2026-15711\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"yes\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"secalert@redhat.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-770\"}]}],\"references\":[{\"url\":\"https://access.redhat.com/security/cve/CVE-2026-15711\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://bugzilla.redhat.com/show_bug.cgi?id=2499924\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://gitlab.gnome.org/GNOME/libsoup/-/issues/515\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://gitlab.gnome.org/GNOME/libsoup/-/issues/515\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-14T20:05:55+00:00",
      "cve": "CVE-2026-15711",
      "id": "CVE-2026-15711",
      "initial_release_date": "2026-07-14T09:52:00+00:00",
      "product_status:known_affected": "16",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "libsoup: SoupWebsocketConnection: libsoup: WebSocket remote denial of service via oversized control frame protocol violation",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-15711.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"cna\": {\"title\": \"Libsoup: soupwebsocketconnection: libsoup: websocket remote denial of service via oversized control frame protocol violation\", \"metrics\": [{\"other\": {\"content\": {\"value\": \"Moderate\", \"namespace\": \"https://access.redhat.com/security/updates/classification/\"}, \"type\": \"Red Hat severity rating\"}}, {\"cvssV3_1\": {\"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\"}, \"format\": \"CVSS\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"A vulnerability was found in libsoup\u0027s WebSocket frame parsing implementation. The library fails to validate length rules specified in RFC 6455 \\u00a75.5, which mandates that all WebSocket control frames (e.g., PING, PONG, CLOSE) contain a payload of 125 bytes or less. A remote, unauthenticated attacker can exploit this by sending a non-compliant, oversized control frame. Because the parser handles this protocol violation improperly instead of throwing an immediate connection termination error, it triggers a internal processing crash, resulting in a remote denial of service (DoS) for applications utilizing libsoup WebSockets.\"}], \"affected\": [{\"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 10\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"packageName\": \"libsoup3\", \"defaultStatus\": \"affected\", \"cpes\": [\"cpe:/o:redhat:enterprise_linux:10\"]}, {\"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 6\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"packageName\": \"libsoup\", \"defaultStatus\": \"unknown\", \"cpes\": [\"cpe:/o:redhat:enterprise_linux:6\"]}, {\"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 7\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"packageName\": \"libsoup\", \"defaultStatus\": \"unknown\", \"cpes\": [\"cpe:/o:redhat:enterprise_linux:7\"]}, {\"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 8\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"packageName\": \"libsoup\", \"defaultStatus\": \"affected\", \"cpes\": [\"cpe:/o:redhat:enterprise_linux:8\"]}, {\"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"packageName\": \"libsoup\", \"defaultStatus\": \"affected\", \"cpes\": [\"cpe:/o:redhat:enterprise_linux:9\"]}], \"references\": [{\"url\": \"https://access.redhat.com/security/cve/CVE-2026-15711\", \"tags\": [\"vdb-entry\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=2499924\", \"name\": \"RHBZ#2499924\", \"tags\": [\"issue-tracking\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://gitlab.gnome.org/GNOME/libsoup/-/issues/515\"}], \"datePublic\": \"2026-07-14T09:52:00.000Z\", \"problemTypes\": [{\"descriptions\": [{\"cweId\": \"CWE-770\", \"description\": \"Allocation of Resources Without Limits or Throttling\", \"lang\": \"en\", \"type\": \"CWE\"}]}], \"x_redhatCweChain\": \"CWE-770: Allocation of Resources Without Limits or Throttling\", \"workarounds\": [{\"lang\": \"en\", \"value\": \"Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.\"}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2026-07-14T09:46:13.021Z\", \"value\": \"Reported to Red Hat.\"}, {\"lang\": \"en\", \"time\": \"2026-07-14T09:52:00.000Z\", \"value\": \"Made public.\"}], \"credits\": [{\"lang\": \"en\", \"value\": \"Red Hat would like to thank Sebasti\\u00e1n Alba Vives (@Sebasteuo / 0xS4bb1) for reporting this issue.\"}], \"providerMetadata\": {\"orgId\": \"53f830b8-0a3f-465b-8143-3b8a9948e749\", \"shortName\": \"redhat\", \"dateUpdated\": \"2026-07-14T19:45:47.784Z\"}, \"x_generator\": {\"engine\": \"cvelib 1.8.0\"}}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-15711\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-07-15T14:10:43.407984Z\"}}}], \"references\": [{\"url\": \"https://gitlab.gnome.org/GNOME/libsoup/-/issues/515\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-07-15T14:11:02.297Z\"}}]}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-15711\", \"assignerOrgId\": \"53f830b8-0a3f-465b-8143-3b8a9948e749\", \"state\": \"PUBLISHED\", \"assignerShortName\": \"redhat\", \"dateReserved\": \"2026-07-14T09:45:31.488Z\", \"datePublished\": \"2026-07-14T19:45:47.784Z\", \"dateUpdated\": \"2026-07-15T14:11:08.927Z\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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

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.