CVE-2026-48095

{"id": "CVE-2026-48095", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.8}]}, "published": "2026-06-05T15:16:53.520", "references": [{"url": "https://securitylab.github.com/advisories/GHSL-2026-140_7-Zip/", "tags": ["Exploit", "Third Party Advisory"], "source": "security-advisories@github.com"}, {"url": "https://sourceforge.net/p/sevenzip/discussion/45797/thread/555e132ba4", "tags": ["Product", "Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://securitylab.github.com/advisories/GHSL-2026-140_7-Zip/", "tags": ["Exploit", "Third Party Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-190"}, {"lang": "en", "value": "CWE-787"}]}], "descriptions": [{"lang": "en", "value": "7-Zip is a file archiver with a high compression ratio. Versions 26.00 and prior contain a heap buffer overflow vulnerability caused by an under-allocation in the NTFS compressed stream buffer (GetCuSize shift UB), potentially allowing attackers to cause arbitrary code execution or application crashes. CInStream::GetCuSize() in the NTFS handler computes the compression-unit buffer size as (UInt32)1 << (BlockSizeLog + CompressionUnit), and a crafted image with ClusterSizeLog >= 28 and CompressionUnit == 4 drives the exponent to 32, which is undefined behavior and collapses on x86/x64 so _inBuf is allocated as 1 byte. ReadStream_FALSE then writes up to 256 MB of attacker-controlled data into that 1-byte buffer in 64 KB iterations, and because the CInStream object sits only 304 bytes after _inBuf, its vtable pointer is overwritten and the next dispatched call achieves a vtable hijack. On 32-bit builds the overflow is unconditionally reached; on 64-bit it requires the parallel 8 GB _outBuf allocation to succeed, otherwise failing closed to denial of service. The NTFS handler is enabled by default in stock 7z.dll and, via signature-based fallback matching \"NTFS \" at offset 3, will open a crafted image regardless of file extension during extraction or testing. Version 26.01 fixes the issue."}], "lastModified": "2026-06-08T20:17:01.873", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:7-zip:7-zip:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "37D7B6D1-E38F-47F8-857B-5AA58D6E677A", "versionEndExcluding": "26.01"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}