CVE-2026-32875 (GCVE-0-2026-32875)

Vulnerability from cvelistv5 – Published: 2026-03-20 01:35 – Updated: 2026-06-30 12:07
VLAI?
Title
UltraJSON has an integer overflow handling large indent leads to buffer overflow or infinite loop
Summary
UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.10 through 5.11.0 are vulnerable to buffer overflow or infinite loop through large indent handling. ujson.dumps() crashes the Python interpreter (segmentation fault) when the product of the indent parameter and the nested depth of the input exceeds INT32_MAX. It can also get stuck in an infinite loop if the indent is a large negative number. Both are caused by an integer overflow/underflow whilst calculating how much memory to reserve for indentation. And both can be used to achieve denial of service. To be vulnerable, a service must call ujson.dump()/ujson.dumps()/ujson.encode() whilst giving untrusted users control over the indent parameter and not restrict that indentation to reasonably small non-negative values. A service may also be vulnerable to the infinite loop if it uses a fixed negative indent. An underflow always occurs for any negative indent when the input data is at least one level nested but, for small negative indents, the underflow is usually accidentally rectified by another overflow. This issue has been fixed in version 5.12.0.
Severity ?
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-190 - Integer Overflow or Wraparound
  • CWE-787 - Out-of-bounds Write
  • CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')
Assigner
References
Impacted products
Vendor Product Version
ultrajson ultrajson Affected: >= 5.1.0, < 5.12.0
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-32875",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-25T14:32:02.675720Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-25T14:32:46.613Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "affected": [
          {
            "cpes": [
              "cpe:/a:redhat:openstack:16.2"
            ],
            "defaultStatus": "unaffected",
            "product": "Red Hat OpenStack Platform 16.2",
            "vendor": "Red Hat"
          },
          {
            "cpes": [
              "cpe:/a:redhat:openstack:17.1"
            ],
            "defaultStatus": "unaffected",
            "product": "Red Hat OpenStack Platform 17.1",
            "vendor": "Red Hat"
          },
          {
            "cpes": [
              "cpe:/a:redhat:openstack:18.0"
            ],
            "defaultStatus": "unaffected",
            "product": "Red Hat OpenStack Platform 18.0",
            "vendor": "Red Hat"
          }
        ],
        "datePublic": "2026-03-20T01:35:23.362Z",
        "descriptions": [
          {
            "lang": "en",
            "value": "A flaw was found in UltraJSON, a fast JSON encoder and decoder. This vulnerability allows a remote attacker to cause a denial of service (DoS) by providing a specially crafted large positive or negative indent value to the JSON serialization functions. This can lead to a buffer overflow, causing the Python interpreter to crash, or an infinite loop, making the application unresponsive. The issue stems from an integer overflow or underflow during memory allocation for indentation."
          }
        ],
        "metrics": [
          {
            "other": {
              "content": {
                "namespace": "https://access.redhat.com/security/updates/classification/",
                "value": "Important"
              },
              "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-190",
                "description": "Integer Overflow or Wraparound",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-30T12:07:40.220Z",
          "orgId": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
          "shortName": "redhat-SADP"
        },
        "references": [
          {
            "tags": [
              "vdb-entry",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/security/cve/CVE-2026-32875"
          },
          {
            "name": "RHBZ#2449400",
            "tags": [
              "issue-tracking",
              "x_refsource_REDHAT"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2449400"
          },
          {
            "tags": [
              "x_sadp-csaf-vex"
            ],
            "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-32875.json"
          }
        ],
        "timeline": [
          {
            "lang": "en",
            "time": "2026-03-20T03:02:30.994Z",
            "value": "Reported to Red Hat."
          },
          {
            "lang": "en",
            "time": "2026-03-20T01:35:23.362Z",
            "value": "Made public."
          }
        ],
        "title": "ultrajson: UltraJSON: Denial of Service via large indent parameter in JSON serialization",
        "x_adpType": "supplier",
        "x_generator": {
          "engine": "sadp-cli 1.0.0"
        }
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "ultrajson",
          "vendor": "ultrajson",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 5.1.0, \u003c 5.12.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.10 through 5.11.0 are vulnerable to buffer overflow or infinite loop through large indent handling. ujson.dumps() crashes the Python interpreter (segmentation fault) when the product of the indent parameter and the nested depth of the input exceeds INT32_MAX. It can also get stuck in an infinite loop if the indent is a large negative number. Both are caused by an integer overflow/underflow whilst calculating how much memory to reserve for indentation. And both can be used to achieve denial of service. To be vulnerable, a service must call ujson.dump()/ujson.dumps()/ujson.encode() whilst giving untrusted users control over the indent parameter and not restrict that indentation to reasonably small non-negative values. A service may also be vulnerable to the infinite loop if it uses a fixed negative indent. An underflow always occurs for any negative indent when the input data is at least one level nested but, for small negative indents, the underflow is usually accidentally rectified by another overflow. This issue has been fixed in version 5.12.0."
        }
      ],
      "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"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-190",
              "description": "CWE-190: Integer Overflow or Wraparound",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-787",
              "description": "CWE-787: Out-of-bounds Write",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-835",
              "description": "CWE-835: Loop with Unreachable Exit Condition (\u0027Infinite Loop\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-20T01:35:23.362Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/ultrajson/ultrajson/security/advisories/GHSA-c8rr-9gxc-jprv",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/ultrajson/ultrajson/security/advisories/GHSA-c8rr-9gxc-jprv"
        },
        {
          "name": "https://github.com/ultrajson/ultrajson/issues/700",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/ultrajson/ultrajson/issues/700"
        },
        {
          "name": "https://github.com/ultrajson/ultrajson/commit/486bd4553dc471a1de11613bc7347a6b318e37ea",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/ultrajson/ultrajson/commit/486bd4553dc471a1de11613bc7347a6b318e37ea"
        }
      ],
      "source": {
        "advisory": "GHSA-c8rr-9gxc-jprv",
        "discovery": "UNKNOWN"
      },
      "title": "UltraJSON has an integer overflow handling large indent leads to buffer overflow or infinite loop"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-32875",
    "datePublished": "2026-03-20T01:35:23.362Z",
    "dateReserved": "2026-03-16T21:03:44.420Z",
    "dateUpdated": "2026-06-30T12:07:40.220Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

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.