FKIE_CVE-2026-68498

Vulnerability from fkie_nvd - Published: 2026-10-16 22:17 - Updated: 2026-10-19 21:14
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
StreamReadConstraints.maxNameLength (default 50,000 characters) is intended to bound how much memory a single JSON Object property name can consume while being parsed, independently of the much larger maxStringLength (default 100,000,000 characters) that bounds ordinary string values. For parsers built over character input — Reader, String or char[] sources, all served by ReaderBasedJsonParser — that bound is not applied while the name is being accumulated. The code path instead re-uses the string-value length check, which is roughly 2000x larger by default. In the character-input slow path, ReaderBasedJsonParser._parseName2() accumulates the name into the TextBuffer and, when a segment fills, calls TextBuffer.finishCurrentSegment(), which validates only maxStringLength. The correct check, StreamReadConstraints.validateNameLength(int), is reached afterwards in CharsToNameCanonicalizer.findSymbol(), once the entire name has been scanned to its closing quote. By that point the full name — up to maxStringLength characters — has already been buffered in memory. A remote attacker who can have a single sufficiently long JSON Object property name parsed through this path can force allocation on the order of 100,000,000 characters (approximately 200 MB, with segment bookkeeping pushing real peak usage higher) before any StreamConstraintsException is thrown, instead of the approximately 50,000-character (about 100 KB) bound the API promises. Repeating this across concurrent requests can exhaust the heap and crash the process. No authentication or user interaction is required. Because StreamReadConstraints.maxDocumentLength is disabled by default (-1), nothing else bounds the token first, so the issue is exploitable under default configuration. Byte-input parsers are not affected: UTF8StreamJsonParser, UTF8DataInputJsonParser and the non-blocking (async) parsers re-validate maxNameLength on every growth of the name-decode buffer via ParserBase._growNameDecodeBuffer(), rejecting an oversized name after allocating only tens of kilobytes. Applications are exposed when untrusted JSON is parsed from a String, Reader or char[] — for example an HTTP request body already read into a String — rather than from raw UTF-8 bytes. This issue affects com.fasterxml.jackson.core:jackson-core from 2.16.0 and tools.jackson.core:jackson-core from 3.0.0. Releases before 2.16.0 are not affected, because StreamReadConstraints.maxNameLength was first introduced in jackson-core 2.16.0.
References
36c7be3b-2937-45df-85ea-ca7133ea542chttps://github.com/FasterXML/jackson-core/blob/2.x/release-notes/VERSION-2.x
36c7be3b-2937-45df-85ea-ca7133ea542chttps://github.com/FasterXML/jackson-core/blob/3.x/release-notes/VERSION
36c7be3b-2937-45df-85ea-ca7133ea542chttps://github.com/FasterXML/jackson-core/commit/2cd206de1163e3fcff7bdaca425274f00668b075
36c7be3b-2937-45df-85ea-ca7133ea542chttps://github.com/FasterXML/jackson-core/pull/1643
36c7be3b-2937-45df-85ea-ca7133ea542chttps://github.com/FasterXML/jackson-core/security/advisories/GHSA-649p-m576-vr99
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://repo.maven.apache.org/maven2",
          "defaultStatus": "unaffected",
          "packageName": "com.fasterxml.jackson.core:jackson-core",
          "product": "jackson-core",
          "programFiles": [
            "src/main/java/com/fasterxml/jackson/core/json/ReaderBasedJsonParser.java"
          ],
          "programRoutines": [
            {
              "name": "ReaderBasedJsonParser._parseName2"
            }
          ],
          "repo": "https://github.com/FasterXML/jackson-core",
          "vendor": "FasterXML",
          "versions": [
            {
              "lessThan": "2.18.10",
              "status": "affected",
              "version": "2.16.0",
              "versionType": "maven"
            },
            {
              "status": "unaffected",
              "version": "2.18.10",
              "versionType": "maven"
            },
            {
              "lessThan": "2.21.6",
              "status": "affected",
              "version": "2.19.0",
              "versionType": "maven"
            },
            {
              "status": "unaffected",
              "version": "2.21.6",
              "versionType": "maven"
            },
            {
              "lessThan": "2.22.2",
              "status": "affected",
              "version": "2.22.0",
              "versionType": "maven"
            },
            {
              "status": "unaffected",
              "version": "2.22.2",
              "versionType": "maven"
            }
          ]
        },
        {
          "collectionURL": "https://repo.maven.apache.org/maven2",
          "defaultStatus": "unaffected",
          "packageName": "tools.jackson.core:jackson-core",
          "product": "jackson-core",
          "programFiles": [
            "src/main/java/tools/jackson/core/json/ReaderBasedJsonParser.java"
          ],
          "programRoutines": [
            {
              "name": "ReaderBasedJsonParser._parseName2"
            }
          ],
          "repo": "https://github.com/FasterXML/jackson-core",
          "vendor": "FasterXML",
          "versions": [
            {
              "lessThan": "3.1.6",
              "status": "affected",
              "version": "3.0.0",
              "versionType": "maven"
            },
            {
              "status": "unaffected",
              "version": "3.1.6",
              "versionType": "maven"
            },
            {
              "lessThan": "3.2.2",
              "status": "affected",
              "version": "3.2.0",
              "versionType": "maven"
            },
            {
              "status": "unaffected",
              "version": "3.2.2",
              "versionType": "maven"
            }
          ]
        }
      ],
      "source": "36c7be3b-2937-45df-85ea-ca7133ea542c"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "StreamReadConstraints.maxNameLength (default 50,000 characters) is intended to bound how much memory a single JSON Object property name can consume while being parsed, independently of the much larger maxStringLength (default 100,000,000 characters) that bounds ordinary string values. For parsers built over character input \u2014 Reader, String or char[] sources, all served by ReaderBasedJsonParser \u2014 that bound is not applied while the name is being accumulated. The code path instead re-uses the string-value length check, which is roughly 2000x larger by default.\n\n\n\nIn the character-input slow path, ReaderBasedJsonParser._parseName2() accumulates the name into the TextBuffer and, when a segment fills, calls TextBuffer.finishCurrentSegment(), which validates only maxStringLength. The correct check, StreamReadConstraints.validateNameLength(int), is reached afterwards in CharsToNameCanonicalizer.findSymbol(), once the entire name has been scanned to its closing quote. By that point the full name \u2014 up to maxStringLength characters \u2014 has already been buffered in memory.\n\n\n\nA remote attacker who can have a single sufficiently long JSON Object property name parsed through this path can force allocation on the order of 100,000,000 characters (approximately 200 MB, with segment bookkeeping pushing real peak usage higher) before any StreamConstraintsException is thrown, instead of the approximately 50,000-character (about 100 KB) bound the API promises. Repeating this across concurrent requests can exhaust the heap and crash the process. No authentication or user interaction is required. Because StreamReadConstraints.maxDocumentLength is disabled by default (-1), nothing else bounds the token first, so the issue is exploitable under default configuration.\n\n\n\nByte-input parsers are not affected: UTF8StreamJsonParser, UTF8DataInputJsonParser and the non-blocking (async) parsers re-validate maxNameLength on every growth of the name-decode buffer via ParserBase._growNameDecodeBuffer(), rejecting an oversized name after allocating only tens of kilobytes. Applications are exposed when untrusted JSON is parsed from a String, Reader or char[] \u2014 for example an HTTP request body already read into a String \u2014 rather than from raw UTF-8 bytes.\n\n\n\nThis issue affects com.fasterxml.jackson.core:jackson-core from 2.16.0 and tools.jackson.core:jackson-core from 3.0.0. Releases before 2.16.0 are not affected, because StreamReadConstraints.maxNameLength was first introduced in jackson-core 2.16.0."
    }
  ],
  "id": "CVE-2026-68498",
  "lastModified": "2026-10-19T21:14:14.150",
  "metrics": {
    "cvssMetricV31": [
      {
        "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": "36c7be3b-2937-45df-85ea-ca7133ea542c",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-10-16T22:17:25.183",
  "references": [
    {
      "source": "36c7be3b-2937-45df-85ea-ca7133ea542c",
      "url": "https://github.com/FasterXML/jackson-core/blob/2.x/release-notes/VERSION-2.x"
    },
    {
      "source": "36c7be3b-2937-45df-85ea-ca7133ea542c",
      "url": "https://github.com/FasterXML/jackson-core/blob/3.x/release-notes/VERSION"
    },
    {
      "source": "36c7be3b-2937-45df-85ea-ca7133ea542c",
      "url": "https://github.com/FasterXML/jackson-core/commit/2cd206de1163e3fcff7bdaca425274f00668b075"
    },
    {
      "source": "36c7be3b-2937-45df-85ea-ca7133ea542c",
      "url": "https://github.com/FasterXML/jackson-core/pull/1643"
    },
    {
      "source": "36c7be3b-2937-45df-85ea-ca7133ea542c",
      "url": "https://github.com/FasterXML/jackson-core/security/advisories/GHSA-649p-m576-vr99"
    }
  ],
  "sourceIdentifier": "36c7be3b-2937-45df-85ea-ca7133ea542c",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        }
      ],
      "source": "36c7be3b-2937-45df-85ea-ca7133ea542c",
      "type": "Secondary"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    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.