CVE-2026-15709 (GCVE-0-2026-15709)

Vulnerability from cvelistv5 – Published: 2026-07-14 19:41 – Updated: 2026-07-15 12:58
VLAI
Title
Soupwebsocketextensiondeflate: libsoup: libsoup: websocket permessage-deflate unbounded decompression remote denial of service
Summary
A flaw was found in libsoup's WebSocket implementation when using the permessage-deflate extension. The extension's decompression loop (inflate()) processes data in chunks without enforcing an upper boundary limit on the output buffer size. While libsoup limits the incoming compressed frame size via max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate check for decompressed size (max_total_message_size) exists but executes only after inflation is complete, and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS).
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 · CISA-ADP (v2.0.3)
Decision recorded 2026-07-15 12:58 UTC
CWE
  • CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
Impacted products
Date Public
2026-07-14 09:42
Credits
Red Hat would like to thank Tristan Madani for reporting this issue.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-15709",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-15T12:58:14.451474Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-15T12:58:18.795Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://gitlab.gnome.org/GNOME/libsoup/-/issues/511"
          }
        ],
        "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 Tristan Madani for reporting this issue."
        }
      ],
      "datePublic": "2026-07-14T09:42:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "A flaw was found in libsoup\u0027s WebSocket implementation when using the permessage-deflate extension. The extension\u0027s decompression loop (inflate()) processes data in chunks without enforcing an upper boundary limit on the output buffer size. While libsoup limits the incoming compressed frame size via max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate check for decompressed size (max_total_message_size) exists but executes only after inflation is complete, and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS)."
        }
      ],
      "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-409",
              "description": "Improper Handling of Highly Compressed Data (Data Amplification)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-14T19:41:37.331Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "tags": [
            "vdb-entry",
            "x_refsource_REDHAT"
          ],
          "url": "https://access.redhat.com/security/cve/CVE-2026-15709"
        },
        {
          "name": "RHBZ#2499922",
          "tags": [
            "issue-tracking",
            "x_refsource_REDHAT"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2499922"
        },
        {
          "url": "https://gitlab.gnome.org/GNOME/libsoup/-/issues/511"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-07-14T09:34:32.593Z",
          "value": "Reported to Red Hat."
        },
        {
          "lang": "en",
          "time": "2026-07-14T09:42:00.000Z",
          "value": "Made public."
        }
      ],
      "title": "Soupwebsocketextensiondeflate: libsoup: libsoup: websocket permessage-deflate unbounded decompression remote denial of service",
      "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-409: Improper Handling of Highly Compressed Data (Data Amplification)"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2026-15709",
    "datePublished": "2026-07-14T19:41:37.331Z",
    "dateReserved": "2026-07-14T09:32:47.038Z",
    "dateUpdated": "2026-07-15T12:58:18.795Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-15709",
      "date": "2026-09-01",
      "epss": "0.00784",
      "percentile": "0.53555"
    },
    "microsoft_vex": {
      "current_release_date": "2026-07-17T01:01:57.000Z",
      "cve": "CVE-2026-15709",
      "id": "msrc_CVE-2026-15709",
      "initial_release_date": "2026-07-17T01:01:57.000Z",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "Soupwebsocketextensiondeflate: libsoup: libsoup: websocket permessage-deflate unbounded decompression remote denial of service",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-15709.json",
      "version": "1"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-15709\",\"sourceIdentifier\":\"secalert@redhat.com\",\"published\":\"2026-07-14T20:16:57.027\",\"lastModified\":\"2026-07-15T18:20:21.237\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A flaw was found in libsoup\u0027s WebSocket implementation when using the permessage-deflate extension. The extension\u0027s decompression loop (inflate()) processes data in chunks without enforcing an upper boundary limit on the output buffer size. While libsoup limits the incoming compressed frame size via max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate check for decompressed size (max_total_message_size) exists but executes only after inflation is complete, and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS).\"}],\"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\":\"2026-07-15T12:58:14.451474Z\",\"id\":\"CVE-2026-15709\",\"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-409\"}]}],\"references\":[{\"url\":\"https://access.redhat.com/security/cve/CVE-2026-15709\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://bugzilla.redhat.com/show_bug.cgi?id=2499922\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://gitlab.gnome.org/GNOME/libsoup/-/issues/511\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://gitlab.gnome.org/GNOME/libsoup/-/issues/511\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-14T20:06:02+00:00",
      "cve": "CVE-2026-15709",
      "id": "CVE-2026-15709",
      "initial_release_date": "2026-07-14T09:42:00+00:00",
      "product_status:known_affected": "16",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "SoupWebsocketExtensionDeflate: libsoup: libsoup: WebSocket permessage-deflate Unbounded Decompression Remote Denial of Service",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-15709.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"cna\": {\"title\": \"Soupwebsocketextensiondeflate: libsoup: libsoup: websocket permessage-deflate unbounded decompression remote denial of service\", \"credits\": [{\"lang\": \"en\", \"value\": \"Red Hat would like to thank Tristan Madani for reporting this issue.\"}], \"metrics\": [{\"other\": {\"type\": \"Red Hat severity rating\", \"content\": {\"value\": \"Moderate\", \"namespace\": \"https://access.redhat.com/security/updates/classification/\"}}}, {\"format\": \"CVSS\", \"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}], \"affected\": [{\"cpes\": [\"cpe:/o:redhat:enterprise_linux:10\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 10\", \"packageName\": \"libsoup3\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/o:redhat:enterprise_linux:6\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 6\", \"packageName\": \"libsoup\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"unknown\"}, {\"cpes\": [\"cpe:/o:redhat:enterprise_linux:7\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 7\", \"packageName\": \"libsoup\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"unknown\"}, {\"cpes\": [\"cpe:/o:redhat:enterprise_linux:8\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 8\", \"packageName\": \"libsoup\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/o:redhat:enterprise_linux:9\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9\", \"packageName\": \"libsoup\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2026-07-14T09:34:32.593Z\", \"value\": \"Reported to Red Hat.\"}, {\"lang\": \"en\", \"time\": \"2026-07-14T09:42:00.000Z\", \"value\": \"Made public.\"}], \"datePublic\": \"2026-07-14T09:42:00.000Z\", \"references\": [{\"url\": \"https://access.redhat.com/security/cve/CVE-2026-15709\", \"tags\": [\"vdb-entry\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=2499922\", \"name\": \"RHBZ#2499922\", \"tags\": [\"issue-tracking\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://gitlab.gnome.org/GNOME/libsoup/-/issues/511\"}], \"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\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"A flaw was found in libsoup\u0027s WebSocket implementation when using the permessage-deflate extension. The extension\u0027s decompression loop (inflate()) processes data in chunks without enforcing an upper boundary limit on the output buffer size. While libsoup limits the incoming compressed frame size via max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate check for decompressed size (max_total_message_size) exists but executes only after inflation is complete, and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS).\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-409\", \"description\": \"Improper Handling of Highly Compressed Data (Data Amplification)\"}]}], \"providerMetadata\": {\"orgId\": \"53f830b8-0a3f-465b-8143-3b8a9948e749\", \"shortName\": \"redhat\", \"dateUpdated\": \"2026-07-14T19:41:37.331Z\"}, \"x_redhatCweChain\": \"CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)\"}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-15709\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-07-15T12:58:14.451474Z\"}}}], \"references\": [{\"url\": \"https://gitlab.gnome.org/GNOME/libsoup/-/issues/511\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"shortName\": \"CISA-ADP\", \"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"dateUpdated\": \"2026-07-15T12:57:37.820Z\"}}]}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-15709\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-14T19:41:37.331Z\", \"dateReserved\": \"2026-07-14T09:32:47.038Z\", \"assignerOrgId\": \"53f830b8-0a3f-465b-8143-3b8a9948e749\", \"datePublished\": \"2026-07-14T19:41:37.331Z\", \"assignerShortName\": \"redhat\"}",
      "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.