CVE-2025-68131

Published Dec 31, 2025

Last updated 2 months ago

CVSS medium 5.5

Overview

Description: 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.
Source: security-advisories@github.com
NVD status: Analyzed
Products: cbor2

Risk scores

CVSS 4.0

Type: Secondary
Base score: 5.5
Impact score: -
Exploitability score: -
Vector string: 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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Severity: MEDIUM

CVSS 3.1

Type: Primary
Base score: 7.5
Impact score: 3.6
Exploitability score: 3.9
Vector string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Severity: HIGH

Weaknesses

security-advisories@github.com: CWE-212

Hype score: Not currently trending

Configurations

[
  {
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:agronholm:cbor2:*:*:*:*:*:python:*:*",
            "matchCriteriaId": "B7E7A985-D868-475E-BAD5-51FBC147198A",
            "versionEndExcluding": "5.8.0",
            "versionStartIncluding": "3.0.0",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ]
  }
]

References

Sources include official advisories and independent security research.

Overview

Risk scores

CVSS 4.0

CVSS 3.1

Weaknesses

Social media

Configurations

Related CVEs

References