Vulnerability-Lookup

ubuntu-cve-2026-48095

Vulnerability from osv_ubuntu

Published

2026-06-05 15:16

Modified

2026-06-11 13:06

Summary

Details

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.

Severity

8.8 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-48095	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-48095	REPORT
	https://securitylab.github.com/advisories/GHSL-20…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "p7zip",
            "binary_version": "9.20.1~dfsg.1-4+deb7u3build0.14.04.1"
          },
          {
            "binary_name": "p7zip-full",
            "binary_version": "9.20.1~dfsg.1-4+deb7u3build0.14.04.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:14.04:LTS",
        "name": "p7zip",
        "purl": "pkg:deb/ubuntu/p7zip@9.20.1~dfsg.1-4+deb7u3build0.14.04.1?arch=source\u0026distro=trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "9.20.1~dfsg.1-4",
        "9.20.1~dfsg.1-4+deb7u1build0.14.04.1",
        "9.20.1~dfsg.1-4+deb7u2build0.14.04.1",
        "9.20.1~dfsg.1-4+deb7u3build0.14.04.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "p7zip",
            "binary_version": "9.20.1~dfsg.1-4.2ubuntu0.1"
          },
          {
            "binary_name": "p7zip-full",
            "binary_version": "9.20.1~dfsg.1-4.2ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "p7zip",
        "purl": "pkg:deb/ubuntu/p7zip@9.20.1~dfsg.1-4.2ubuntu0.1?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "9.20.1~dfsg.1-4.2",
        "9.20.1~dfsg.1-4.2ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "p7zip",
            "binary_version": "16.02+dfsg-6"
          },
          {
            "binary_name": "p7zip-full",
            "binary_version": "16.02+dfsg-6"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "p7zip",
        "purl": "pkg:deb/ubuntu/p7zip@16.02+dfsg-6?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "16.02+dfsg-4",
        "16.02+dfsg-5",
        "16.02+dfsg-6"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "p7zip",
            "binary_version": "16.02+dfsg-7build1"
          },
          {
            "binary_name": "p7zip-full",
            "binary_version": "16.02+dfsg-7build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "p7zip",
        "purl": "pkg:deb/ubuntu/p7zip@16.02+dfsg-7build1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "16.02+dfsg-7",
        "16.02+dfsg-7build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "p7zip",
            "binary_version": "16.02+dfsg-8"
          },
          {
            "binary_name": "p7zip-full",
            "binary_version": "16.02+dfsg-8"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "p7zip",
        "purl": "pkg:deb/ubuntu/p7zip@16.02+dfsg-8?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "16.02+dfsg-8"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "7zip",
            "binary_version": "21.07+dfsg-4ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "7zip",
        "purl": "pkg:deb/ubuntu/7zip@21.07+dfsg-4ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "21.03~beta+dfsg-6",
        "21.04~beta+dfsg-1",
        "21.06+dfsg-1",
        "21.07+dfsg-1",
        "21.07+dfsg-2",
        "21.07+dfsg-3",
        "21.07+dfsg-4",
        "21.07+dfsg-4ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "7zip",
            "binary_version": "23.01+dfsg-11ubuntu0.1~esm1"
          },
          {
            "binary_name": "7zip-standalone",
            "binary_version": "23.01+dfsg-11ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:24.04:LTS",
        "name": "7zip",
        "purl": "pkg:deb/ubuntu/7zip@23.01+dfsg-11ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "23.01+dfsg-3",
        "23.01+dfsg-7",
        "23.01+dfsg-8",
        "23.01+dfsg-11",
        "23.01+dfsg-11ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "7zip",
            "binary_version": "25.01+dfsg-2"
          },
          {
            "binary_name": "7zip-standalone",
            "binary_version": "25.01+dfsg-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "7zip",
        "purl": "pkg:deb/ubuntu/7zip@25.01+dfsg-2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "24.09+dfsg-7",
        "24.09+dfsg-8",
        "25.00+dfsg-1",
        "25.01+dfsg-1",
        "25.01+dfsg-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "7zip",
            "binary_version": "26.00+dfsg-1"
          },
          {
            "binary_name": "7zip-standalone",
            "binary_version": "26.00+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "7zip",
        "purl": "pkg:deb/ubuntu/7zip@26.00+dfsg-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "25.01+dfsg-2",
        "25.01+dfsg-3",
        "25.01+dfsg-4",
        "25.01+dfsg-5",
        "26.00+dfsg-1"
      ]
    }
  ],
  "aliases": [],
  "details": "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 \u003c\u003c (BlockSizeLog + CompressionUnit), and a crafted image with ClusterSizeLog \u003e= 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.",
  "id": "UBUNTU-CVE-2026-48095",
  "modified": "2026-06-11T13:06:29Z",
  "published": "2026-06-05T15:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-48095"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-48095"
    },
    {
      "type": "REPORT",
      "url": "https://securitylab.github.com/advisories/GHSL-2026-140_7-Zip/"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-48095"
  ]
}

CVE-2026-48095 (GCVE-0-2026-48095)

Vulnerability from cvelistv5 – Published: 2026-06-05 13:57 – Updated: 2026-06-08 19:10

Title

GHSL-2026-140_7-Zip: 7-Zip has a heap buffer overflow via NTFS compressed stream buffer under-allocation

Summary

Severity

8.8 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-08 19:10 UTC

CWE

CWE-787 - Out-of-bounds Write
CWE-190 - Integer Overflow or Wraparound

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://securitylab.github.com/advisories/GHSL-20…	x_refsource_CONFIRM
https://sourceforge.net/p/sevenzip/discussion/457…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
mcmilk	7-Zip	Affected: <= 26.00

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-48095",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-08T19:10:27.520353Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-08T19:10:46.668Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://securitylab.github.com/advisories/GHSL-2026-140_7-Zip/"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "7-Zip",
          "vendor": "mcmilk",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c= 26.00"
            }
          ]
        }
      ],
      "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 \u003c\u003c (BlockSizeLog + CompressionUnit), and a crafted image with ClusterSizeLog \u003e= 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-787",
              "description": "CWE-787: Out-of-bounds Write",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-190",
              "description": "CWE-190: Integer Overflow or Wraparound",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-05T13:57:43.772Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://securitylab.github.com/advisories/GHSL-2026-140_7-Zip/",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://securitylab.github.com/advisories/GHSL-2026-140_7-Zip/"
        },
        {
          "name": "https://sourceforge.net/p/sevenzip/discussion/45797/thread/555e132ba4",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://sourceforge.net/p/sevenzip/discussion/45797/thread/555e132ba4"
        }
      ],
      "source": {
        "advisory": "GHSA-35m9-7297-xx42",
        "discovery": "UNKNOWN"
      },
      "title": "GHSL-2026-140_7-Zip: 7-Zip has a heap buffer overflow via NTFS compressed stream buffer under-allocation"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-48095",
    "datePublished": "2026-06-05T13:57:43.772Z",
    "dateReserved": "2026-05-20T18:40:45.834Z",
    "dateUpdated": "2026-06-08T19:10:46.668Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.