Vulnerability-Lookup

UBUNTU-CVE-2025-68131 (CVE-2025-68131)

Vulnerability from osv_ubuntu – Published: 2025-12-31 02:15 – Updated: 2026-05-20 15:22 – Source website

Details

cbor2 provides encoding and decoding for the Concise Binary Object Representation (CBOR) serialization format. Starting in version 3.0.0 and prior to version 5.8.0, whhen a CBORDecoder instance is reused across multiple decode operations, values marked with the shareable tag (28) persist in memory and can be accessed by subsequent CBOR messages using the sharedref tag (29). This allows an attacker-controlled message to read data from previously decoded messages if the decoder is reused across trust boundaries. Version 5.8.0 patches the issue.

Severity

5.5 (Medium)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

7.5 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2025-68131	REPORT
	https://www.cve.org/CVERecord?id=CVE-2025-68131	REPORT
	https://github.com/agronholm/cbor2/security/advis…	REPORT
	https://github.com/agronholm/cbor2/pull/268	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-cbor2",
            "binary_version": "5.4.2-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "cbor2",
        "purl": "pkg:deb/ubuntu/cbor2@5.4.2-1build1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.2.0-4",
        "5.2.0-4build1",
        "5.4.2-1",
        "5.4.2-1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-cbor2",
            "binary_version": "5.6.2-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "cbor2",
        "purl": "pkg:deb/ubuntu/cbor2@5.6.2-1build1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.4.6-2",
        "5.4.6-2build1",
        "5.5.1-1",
        "5.6.0-1",
        "5.6.1-1",
        "5.6.2-1",
        "5.6.2-1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-cbor2",
            "binary_version": "5.6.5-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "cbor2",
        "purl": "pkg:deb/ubuntu/cbor2@5.6.5-1build1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.6.5-1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-cbor2",
            "binary_version": "5.8.0-2ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "cbor2",
        "purl": "pkg:deb/ubuntu/cbor2@5.8.0-2ubuntu1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.6.5-1build1",
        "5.7.0-1",
        "5.7.1-1",
        "5.8.0-1",
        "5.8.0-2ubuntu1"
      ]
    }
  ],
  "aliases": [],
  "details": "cbor2 provides encoding and decoding for the Concise Binary Object Representation (CBOR) serialization format. Starting in version 3.0.0 and prior to version 5.8.0, whhen a CBORDecoder instance is reused across multiple decode operations, values marked with the shareable tag (28) persist in memory and can be accessed by subsequent CBOR messages using the sharedref tag (29). This allows an attacker-controlled message to read data from previously decoded messages if the decoder is reused across trust boundaries. Version 5.8.0 patches the issue.",
  "id": "UBUNTU-CVE-2025-68131",
  "modified": "2026-05-20T15:22:59Z",
  "published": "2025-12-31T02:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2025-68131"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-68131"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/agronholm/cbor2/security/advisories/GHSA-wcj4-jw5j-44wh"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/agronholm/cbor2/pull/268"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2025-68131"
  ]
}

CVE-2025-68131 (GCVE-0-2025-68131)

Vulnerability from cvelistv5 – Published: 2025-12-31 01:15 – Updated: 2026-01-02 14:37

Title

CBORDecoder reuse can leak shareable values across decode calls

Summary

Severity

5.5 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-01-02 14:22 UTC

CWE

CWE-212 - Improper Removal of Sensitive Information Before Storage or Transfer

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/agronholm/cbor2/security/advis…	x_refsource_CONFIRM
https://github.com/agronholm/cbor2/pull/268	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
agronholm	cbor2	Affected: >= 3.0.0, < 5.8.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-68131",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-01-02T14:22:41.499483Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-01-02T14:37:55.705Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/agronholm/cbor2/security/advisories/GHSA-wcj4-jw5j-44wh"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "cbor2",
          "vendor": "agronholm",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 3.0.0, \u003c 5.8.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "cbor2 provides encoding and decoding for the Concise Binary Object Representation (CBOR) serialization format. Starting in version 3.0.0 and prior to version 5.8.0, whhen a CBORDecoder instance is reused across multiple decode operations, values marked with the shareable tag (28) persist in memory and can be accessed by subsequent CBOR messages using the sharedref tag (29). This allows an attacker-controlled message to read data from previously decoded messages if the decoder is reused across trust boundaries. Version 5.8.0 patches the issue."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 5.5,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-212",
              "description": "CWE-212: Improper Removal of Sensitive Information Before Storage or Transfer",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-12-31T01:15:36.827Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/agronholm/cbor2/security/advisories/GHSA-wcj4-jw5j-44wh",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/agronholm/cbor2/security/advisories/GHSA-wcj4-jw5j-44wh"
        },
        {
          "name": "https://github.com/agronholm/cbor2/pull/268",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/agronholm/cbor2/pull/268"
        }
      ],
      "source": {
        "advisory": "GHSA-wcj4-jw5j-44wh",
        "discovery": "UNKNOWN"
      },
      "title": "CBORDecoder reuse can leak shareable values across decode calls"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2025-68131",
    "datePublished": "2025-12-31T01:15:36.827Z",
    "dateReserved": "2025-12-15T18:05:52.210Z",
    "dateUpdated": "2026-01-02T14:37:55.705Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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.