GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-65637 (GCVE-0-2026-65637)

Vulnerability from cvelistv5 – Published: 2026-08-25 21:49 – Updated: 2026-08-26 15:20
VLAI
Title
Apache Tomcat: HTTP/2 no-authority bypass of strict SNI validation - CVE-2026-32990 fix incomplete
Summary
Improper Input Validation vulnerability in Apache Tomcat due to incomplete fix for CVE-2026-32990. This issue affects Apache Tomcat: from 11.0.20 through 11.0.24, from 10.1.53 through 10.1.57, from 9.0.115 through 9.0.120. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-26 15:20 UTC
CWE
  • CWE-20 - Improper Input Validation
Assigner
References
Impacted products
Vendor Product Version CPE status
Apache Software Foundation Apache Tomcat Affected: 11.0.20 , ≤ 11.0.24 (semver)
Affected: 10.1.53 , ≤ 10.1.57 (semver)
Affected: 9.0.115 , ≤ 9.0.120 (semver)
guessed Create a notification for this product.
Credits
Parag Ambildhuke (https://github.com/paragxa)
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "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"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-65637",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-26T15:20:15.521688Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-26T15:20:30.366Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Apache Tomcat",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "lessThanOrEqual": "11.0.24",
              "status": "affected",
              "version": "11.0.20",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "10.1.57",
              "status": "affected",
              "version": "10.1.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "9.0.120",
              "status": "affected",
              "version": "9.0.115",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Parag Ambildhuke (https://github.com/paragxa)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eImproper Input Validation vulnerability in Apache Tomcat due to incomplete fix for CVE-2026-32990.\u003c/p\u003e\u003cp\u003eThis issue affects Apache Tomcat: from 11.0.20 through 11.0.24, from 10.1.53 through 10.1.57, from 9.0.115 through 9.0.120.\u003c/p\u003e\u003cp\u003eUsers are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.\u003c/p\u003e"
            }
          ],
          "value": "Improper Input Validation vulnerability in Apache Tomcat due to incomplete fix for CVE-2026-32990.\n\n\n\nThis issue affects Apache Tomcat: from 11.0.20 through 11.0.24, from 10.1.53 through 10.1.57, from 9.0.115 through 9.0.120.\n\n\n\nUsers are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue."
        }
      ],
      "metrics": [
        {
          "other": {
            "content": {
              "text": "moderate"
            },
            "type": "Textual description of severity"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20 Improper Input Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-25T21:49:13.127Z",
        "orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
        "shortName": "apache"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.apache.org/thread/djog953z1ohsyt25bdvhfzbmsy22vgcj"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Apache Tomcat: HTTP/2 no-authority bypass of strict SNI validation - CVE-2026-32990 fix incomplete",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
    "assignerShortName": "apache",
    "cveId": "CVE-2026-65637",
    "datePublished": "2026-08-25T21:49:13.127Z",
    "dateReserved": "2026-07-22T14:38:10.136Z",
    "dateUpdated": "2026-08-26T15:20:30.366Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-65637",
      "date": "2026-09-16",
      "epss": "0.00754",
      "percentile": "0.53324"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-65637\",\"sourceIdentifier\":\"security@apache.org\",\"published\":\"2026-08-25T22:17:05.177\",\"lastModified\":\"2026-08-27T15:19:42.247\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Improper Input Validation vulnerability in Apache Tomcat due to incomplete fix for CVE-2026-32990.\\n\\n\\n\\nThis issue affects Apache Tomcat: from 11.0.20 through 11.0.24, from 10.1.53 through 10.1.57, from 9.0.115 through 9.0.120.\\n\\n\\n\\nUsers are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.\"}],\"affected\":[{\"source\":\"security@apache.org\",\"affectedData\":[{\"vendor\":\"Apache Software Foundation\",\"product\":\"Apache Tomcat\",\"defaultStatus\":\"unaffected\",\"versions\":[{\"version\":\"11.0.20\",\"lessThanOrEqual\":\"11.0.24\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"10.1.53\",\"lessThanOrEqual\":\"10.1.57\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"9.0.115\",\"lessThanOrEqual\":\"9.0.120\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":9.8,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":5.9}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-08-26T15:20:15.521688Z\",\"id\":\"CVE-2026-65637\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"yes\"},{\"technicalImpact\":\"total\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security@apache.org\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-20\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"9.0.115\",\"versionEndExcluding\":\"9.0.121\",\"matchCriteriaId\":\"0267823D-98C8-4283-B198-185275D06486\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"10.1.53\",\"versionEndExcluding\":\"10.1.58\",\"matchCriteriaId\":\"85549589-C5B3-4093-ABF2-37528529AE65\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"11.0.20\",\"versionEndExcluding\":\"11.0.25\",\"matchCriteriaId\":\"3070A357-ABBD-4CE7-894B-CAB8F8E9F342\"}]}]}],\"references\":[{\"url\":\"https://lists.apache.org/thread/djog953z1ohsyt25bdvhfzbmsy22vgcj\",\"source\":\"security@apache.org\",\"tags\":[\"Vendor Advisory\",\"Mailing List\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-09T11:02:34+00:00",
      "cve": "CVE-2026-65637",
      "id": "CVE-2026-65637",
      "initial_release_date": "2026-08-25T21:49:13.127000+00:00",
      "product_status:fixed": "4",
      "product_status:known_affected": "2",
      "product_status:known_not_affected": "1",
      "product_status:under_investigation": "50",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "Apache Tomcat: Apache Tomcat: Improper Input Validation allows HTTP/2 no-authority bypass of strict SNI validation",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-65637.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-09-15T01:44:11Z",
      "cve": "CVE-2026-65637",
      "id": "CVE-2026-65637",
      "initial_release_date": "2026-08-27T00:25:35Z",
      "product_status:first_fixed": "164",
      "product_status:known_affected": "263",
      "product_status:known_not_affected": "1",
      "product_status:recommended": "182",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-65637",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-65637.json",
      "version": "8"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 9.8, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"CRITICAL\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"HIGH\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-65637\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-08-26T15:20:15.521688Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-08-26T15:20:26.740Z\"}}], \"cna\": {\"title\": \"Apache Tomcat: HTTP/2 no-authority bypass of strict SNI validation - CVE-2026-32990 fix incomplete\", \"source\": {\"discovery\": \"EXTERNAL\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Parag Ambildhuke (https://github.com/paragxa)\"}], \"metrics\": [{\"other\": {\"type\": \"Textual description of severity\", \"content\": {\"text\": \"moderate\"}}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"vendor\": \"Apache Software Foundation\", \"product\": \"Apache Tomcat\", \"versions\": [{\"status\": \"affected\", \"version\": \"11.0.20\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"11.0.24\"}, {\"status\": \"affected\", \"version\": \"10.1.53\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"10.1.57\"}, {\"status\": \"affected\", \"version\": \"9.0.115\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"9.0.120\"}], \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://lists.apache.org/thread/djog953z1ohsyt25bdvhfzbmsy22vgcj\", \"tags\": [\"vendor-advisory\"]}], \"x_generator\": {\"engine\": \"Vulnogram 0.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"Improper Input Validation vulnerability in Apache Tomcat due to incomplete fix for CVE-2026-32990.\\n\\n\\n\\nThis issue affects Apache Tomcat: from 11.0.20 through 11.0.24, from 10.1.53 through 10.1.57, from 9.0.115 through 9.0.120.\\n\\n\\n\\nUsers are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eImproper Input Validation vulnerability in Apache Tomcat due to incomplete fix for CVE-2026-32990.\u003c/p\u003e\u003cp\u003eThis issue affects Apache Tomcat: from 11.0.20 through 11.0.24, from 10.1.53 through 10.1.57, from 9.0.115 through 9.0.120.\u003c/p\u003e\u003cp\u003eUsers are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.\u003c/p\u003e\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-20\", \"description\": \"CWE-20 Improper Input Validation\"}]}], \"providerMetadata\": {\"orgId\": \"f0158376-9dc2-43b6-827c-5f631a4d8d09\", \"shortName\": \"apache\", \"dateUpdated\": \"2026-08-25T21:49:13.127Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-65637\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-08-26T15:20:30.366Z\", \"dateReserved\": \"2026-07-22T14:38:10.136Z\", \"assignerOrgId\": \"f0158376-9dc2-43b6-827c-5f631a4d8d09\", \"datePublished\": \"2026-08-25T21:49:13.127Z\", \"assignerShortName\": \"apache\"}",
      "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.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.