CVE-2026-54447

Insecure file permissions expose OAuth token, allowing other users to hijack Garmin Connect accounts.

• CVSS 8.4
• 732
• Configuration Issues
• Local

garminconnect is a Python 3 API wrapper for Garmin Connect that retrieves statistics and manages activities. Prior to 0.3.5, garminconnect/client.py Client.dump creates the OAuth token directory and garmin_tokens.json without explicit owner-only modes, so a permissive umask such as 022 can leave the directory mode at 0755 and the token file mode at 0644. garmin_tokens.json contains di_refresh_token, and another unprivileged user on a shared Linux or macOS host can read the token and obtain persistent access to the victim's Garmin Connect account, including health, fitness, activity, and device data. The Garmin.login tokenstore path is affected, and a pre-existing loosely permissioned token file remains exposed until rewritten or manually restricted. This issue is fixed in version 0.3.5.

CVE

CVE-2026-54447

CWE

732

CVSS base score

8.4

Published

2026-09-14

OWASP

A03 Sensitive Data Exposure

Orthogonal defect classification

Interface

Code defect classification

Missing Check

Category

Configuration Issues

Subcategory

Insecure Direct Object References (IDOR)

Accessibility scope

Local

Impact

Unauthorized Access

Affected component

garminconnect

Fixed by upgrading

Yes

Solution

Upgrade garminconnect to version 0.3.5 or later.

import os
import json
from pathlib import Path

class Client:
    def __init__(self, token_dir: str):
        self.token_path = Path(token_dir) / "garmin_tokens.json"

    def dump(self, token_data: dict):
        # VULNERABLE: creates token directory and file with default permissions
        os.makedirs(self.token_path.parent, exist_ok=True)
        with open(self.token_path, "w") as f:
            json.dump(token_data, f)

import os
import json
from pathlib import Path
import stat

class Client:
    def __init__(self, token_dir: str):
        self.token_path = Path(token_dir) / "garmin_tokens.json"

    def dump(self, token_data: dict):
        # FIX: create directory and file with owner‑only permissions
        os.makedirs(self.token_path.parent, mode=0o700, exist_ok=True)
        fd = os.open(self.token_path, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
        with os.fdopen(fd, "w") as f:
            json.dump(token_data, f)

@misc{vaitp:cve202654447,
  title        = {{Insecure file permissions expose OAuth token, allowing other users to hijack Garmin Connect accounts.}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2026},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2026-54447},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2026-54447/}}
}