CVE-2026-91776

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

• https://github.com/FasterXML/jackson-databind/issues/6203 36c7be3b-2937-45df-85ea-ca7133ea542c
• https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-wv8q-qhhj-9h54 36c7be3b-2937-45df-85ea-ca7133ea542c
• https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-wv8q-qhhj-9h54 134c704f-9b21-4f2e-91b3-4a467353bcc0

The full cvelistV5 record. Download as CVE-2026-91776.json.

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-91776",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-23T14:02:42.582789Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-23T14:03:16.129Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-wv8q-qhhj-9h54"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://repo1.maven.org/maven2",
          "defaultStatus": "unaffected",
          "packageName": "com.fasterxml.jackson.core:jackson-databind",
          "product": "jackson-databind",
          "programRoutines": [
            {
              "name": "com.fasterxml.jackson.databind.jsontype.impl.TypeDeserializerBase._findDeserializer"
            }
          ],
          "repo": "https://github.com/FasterXML/jackson-databind",
          "vendor": "FasterXML",
          "versions": [
            {
              "lessThanOrEqual": "2.18.10",
              "status": "affected",
              "version": "2.0.0",
              "versionType": "maven"
            },
            {
              "lessThanOrEqual": "2.21.6",
              "status": "affected",
              "version": "2.19.0",
              "versionType": "maven"
            },
            {
              "lessThanOrEqual": "2.22.2",
              "status": "affected",
              "version": "2.22.0",
              "versionType": "maven"
            }
          ]
        },
        {
          "collectionURL": "https://repo1.maven.org/maven2",
          "defaultStatus": "unaffected",
          "packageName": "tools.jackson.core:jackson-databind",
          "product": "jackson-databind",
          "programRoutines": [
            {
              "name": "tools.jackson.databind.jsontype.impl.TypeDeserializerBase._findDeserializer"
            }
          ],
          "repo": "https://github.com/FasterXML/jackson-databind",
          "vendor": "FasterXML",
          "versions": [
            {
              "lessThanOrEqual": "3.1.6",
              "status": "affected",
              "version": "3.0.0",
              "versionType": "maven"
            },
            {
              "lessThanOrEqual": "3.2.2",
              "status": "affected",
              "version": "3.2.0",
              "versionType": "maven"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Daniel Birtwhistle (dabirt)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "<p>TypeDeserializerBase._findDeserializer() in FasterXML jackson-databind caches the resolved deserializer under the raw, attacker-supplied type ID. When name-based polymorphism is configured with a fallback, for example @JsonTypeInfo(use = Id.NAME, defaultImpl = ...), every distinct unrecognized type ID resolves to the same fallback deserializer but is retained as its own key in the _deserializers map. That map has no configurable bound and lives for the lifetime of the type deserializer, so an attacker who can repeatedly supply fresh unknown type IDs causes monotonic memory retention across requests. The reporter observed 10,000 retained entries from 10,000 distinct unknown IDs, against a single entry for a control that repeated one unknown ID the same number of times, isolating attacker-controlled key cardinality from request volume. Exploitation requires an application that enables name-based polymorphism with a defaultImpl or equivalent fallback, accepts attacker-influenced type IDs, and reuses a long-lived ObjectMapper across requests. The fix stops caching fallback resolutions for unrecognized IDs and bounds both the number of cached entries and the length of a cacheable type ID.</p>"
            }
          ],
          "value": "TypeDeserializerBase._findDeserializer() in FasterXML jackson-databind caches the resolved deserializer under the raw, attacker-supplied type ID. When name-based polymorphism is configured with a fallback, for example @JsonTypeInfo(use = Id.NAME, defaultImpl = ...), every distinct unrecognized type ID resolves to the same fallback deserializer but is retained as its own key in the _deserializers map. That map has no configurable bound and lives for the lifetime of the type deserializer, so an attacker who can repeatedly supply fresh unknown type IDs causes monotonic memory retention across requests. The reporter observed 10,000 retained entries from 10,000 distinct unknown IDs, against a single entry for a control that repeated one unknown ID the same number of times, isolating attacker-controlled key cardinality from request volume. Exploitation requires an application that enables name-based polymorphism with a defaultImpl or equivalent fallback, accepts attacker-influenced type IDs, and reuses a long-lived ObjectMapper across requests. The fix stops caching fallback resolutions for unrecognized IDs and bounds both the number of cached entries and the length of a cacheable type ID."
        }
      ],
      "metrics": [
        {
          "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",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400 Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-23T02:17:50.480Z",
        "orgId": "36c7be3b-2937-45df-85ea-ca7133ea542c",
        "shortName": "HeroDevs"
      },
      "references": [
        {
          "name": "GHSA-wv8q-qhhj-9h54",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-wv8q-qhhj-9h54"
        },
        {
          "name": "FasterXML/jackson-databind#6203",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/FasterXML/jackson-databind/issues/6203"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "<p>Upgrade to com.fasterxml.jackson.core:jackson-databind 2.18.11, 2.21.7 or 2.22.3, or to tools.jackson.core:jackson-databind 3.1.7 or 3.2.3. Lines 2.0.x through 2.17.x, 2.19.x, 2.20.x and 3.0.x received no fix on their own branch and are no longer maintained upstream.</p>"
            }
          ],
          "value": "Upgrade to com.fasterxml.jackson.core:jackson-databind 2.18.11, 2.21.7 or 2.22.3, or to tools.jackson.core:jackson-databind 3.1.7 or 3.2.3. Lines 2.0.x through 2.17.x, 2.19.x, 2.20.x and 3.0.x received no fix on their own branch and are no longer maintained upstream."
        }
      ],
      "title": "jackson-databind: unbounded growth of the type id cache in TypeDeserializerBase retains every unknown raw type ID",
      "workarounds": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "<p>Where the polymorphic shape allows it, avoid defaultImpl or another catch-all fallback for name-based type resolution so that unrecognized type IDs fail rather than resolving, or restrict accepted type IDs with a custom TypeIdResolver that rejects unknown names before resolution. Shortening ObjectMapper or type deserializer lifetime limits accumulation but does not eliminate it.</p>"
            }
          ],
          "value": "Where the polymorphic shape allows it, avoid defaultImpl or another catch-all fallback for name-based type resolution so that unrecognized type IDs fail rather than resolving, or restrict accepted type IDs with a custom TypeIdResolver that rejects unknown names before resolution. Shortening ObjectMapper or type deserializer lifetime limits accumulation but does not eliminate it."
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "36c7be3b-2937-45df-85ea-ca7133ea542c",
    "assignerShortName": "HeroDevs",
    "cveId": "CVE-2026-91776",
    "datePublished": "2026-09-23T02:17:50.480Z",
    "dateReserved": "2026-09-15T01:22:24.203Z",
    "dateUpdated": "2026-09-23T14:03:16.129Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}