Vulnerability-Lookup

CVE-2026-55195 (GCVE-0-2026-55195)

Vulnerability from cvelistv5 – Published: 2026-07-08 20:30 – Updated: 2026-07-09 14:06

Title

py7zr: Decompression bomb (zip bomb) denial of service via unchecked extraction size

Summary

py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, py7zr's Worker.decompress() extracted archive entries without tracking total decompressed size, allowing a crafted .7z file such as a 15.6 KB archive that expands to 100 MB to exhaust disk or memory before extraction completes. This issue is fixed in version 1.1.3.

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-09 14:05 UTC

CWE

CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/miurahr/py7zr/security/advisor…	x_refsource_CONFIRM
https://github.com/miurahr/py7zr/commit/28faf107b…	x_refsource_MISC
https://github.com/miurahr/py7zr/releases/tag/v1.1.3	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
miurahr	py7zr	Affected: < 1.1.3	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
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          {
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                "id": "CVE-2026-55195",
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                  },
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                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-09T14:05:14.472398Z",
                "version": "2.0.3"
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            }
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          {
            "tags": [
              "exploit"
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          }
        ],
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      }
    ],
    "cna": {
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            }
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        }
      ],
      "metrics": [
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            "attackComplexity": "LOW",
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            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
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            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
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            "vulnIntegrityImpact": "NONE"
          }
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      ],
      "problemTypes": [
        {
          "descriptions": [
            {
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              "description": "CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
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          "url": "https://github.com/miurahr/py7zr/security/advisories/GHSA-gjrg-mpp7-g774"
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      "title": "py7zr: Decompression bomb (zip bomb) denial of service via unchecked extraction size"
    }
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      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
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      "title": "py7zr: py7zr: Denial of Service via decompression bomb in 7zip archive extraction",
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}

FKIE_CVE-2026-55195

Vulnerability from fkie_nvd - Published: 2026-07-08 21:16 - Updated: 2026-07-10 19:06

Severity

8.7 (High) - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/miurahr/py7zr/commit/28faf107b64374fa5a02bfb93aa2024e281ca97b
	security-advisories@github.com	https://github.com/miurahr/py7zr/releases/tag/v1.1.3
	security-advisories@github.com	https://github.com/miurahr/py7zr/security/advisories/GHSA-gjrg-mpp7-g774
	134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/miurahr/py7zr/security/advisories/GHSA-gjrg-mpp7-g774

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "py7zr",
          "vendor": "miurahr",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.1.3"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, py7zr\u0027s Worker.decompress() extracted archive entries without tracking total decompressed size, allowing a crafted .7z file such as a 15.6 KB archive that expands to 100 MB to exhaust disk or memory before extraction completes. This issue is fixed in version 1.1.3."
    }
  ],
  "id": "CVE-2026-55195",
  "lastModified": "2026-07-10T19:06:45.623",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 8.7,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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",
          "version": "4.0",
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        },
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        "type": "Secondary"
      }
    ],
    "ssvcV203": [
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          "options": [
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  "references": [
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      "url": "https://github.com/miurahr/py7zr/commit/28faf107b64374fa5a02bfb93aa2024e281ca97b"
    },
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      "source": "security-advisories@github.com",
      "url": "https://github.com/miurahr/py7zr/releases/tag/v1.1.3"
    },
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      "url": "https://github.com/miurahr/py7zr/security/advisories/GHSA-gjrg-mpp7-g774"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/miurahr/py7zr/security/advisories/GHSA-gjrg-mpp7-g774"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
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}

GHSA-GJRG-MPP7-G774

Vulnerability from github – Published: 2026-06-19 21:16 – Updated: 2026-06-19 21:16

Summary

py7zr: Decompression bomb (zip bomb) denial of service via unchecked extraction size

Details

py7zr's Worker.decompress() extracts archive entries without tracking total decompressed size. A crafted .7z file can exhaust disk or memory before the extraction completes.

Measured: 15.6 KB archive → 100 MB output (6,556:1 ratio).

Proof of concept:

import py7zr, tempfile, os

# create bomb: compress 100MB of zeros into ~15KB
bomb_path = tempfile.mktemp(suffix='.7z')
with py7zr.SevenZipFile(bomb_path, 'w') as z:
    import io
    z.writef(io.BytesIO(b'\x00' * 100 * 1024 * 1024), 'bomb.bin')

print(f'archive size: {os.path.getsize(bomb_path):,} bytes')

# extract — no size check
with py7zr.SevenZipFile(bomb_path, 'r') as z:
    z.extractall(path=tempfile.mkdtemp())

print('extracted 100 MB from ~15 KB archive')

Root cause: Worker.decompress() in py7zr/worker.py writes decompressed data directly to disk without a running total or configurable size limit. There is no equivalent of Python's zipfile max_size parameter.

Fix: track cumulative decompressed bytes and raise before writing if a limit is exceeded:

MAX_EXTRACT_SIZE = 2 * 1024 ** 3  # 2 GB default, configurable

total = 0
for chunk in decompressed_chunks:
    total += len(chunk)
    if total > MAX_EXTRACT_SIZE:
        raise py7zr.exceptions.DecompressionBombError(
            f'Extraction aborted: decompressed size exceeded {MAX_EXTRACT_SIZE} bytes'
        )
    outfile.write(chunk)

Tested on py7zr 0.22.0, Python 3.12, Ubuntu 22.04.

Severity

6.9 (Medium)


                  
                    CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.1.2"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "py7zr"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55195"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-409"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-19T21:16:29Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "py7zr\u0027s `Worker.decompress()` extracts archive entries without tracking total decompressed size. A crafted `.7z` file can exhaust disk or memory before the extraction completes.\n\nMeasured: 15.6 KB archive \u2192 100 MB output (6,556:1 ratio).\n\n**Proof of concept:**\n\n```python\nimport py7zr, tempfile, os\n\n# create bomb: compress 100MB of zeros into ~15KB\nbomb_path = tempfile.mktemp(suffix=\u0027.7z\u0027)\nwith py7zr.SevenZipFile(bomb_path, \u0027w\u0027) as z:\n    import io\n    z.writef(io.BytesIO(b\u0027\\x00\u0027 * 100 * 1024 * 1024), \u0027bomb.bin\u0027)\n\nprint(f\u0027archive size: {os.path.getsize(bomb_path):,} bytes\u0027)\n\n# extract \u2014 no size check\nwith py7zr.SevenZipFile(bomb_path, \u0027r\u0027) as z:\n    z.extractall(path=tempfile.mkdtemp())\n\nprint(\u0027extracted 100 MB from ~15 KB archive\u0027)\n```\n\n**Root cause:** `Worker.decompress()` in `py7zr/worker.py` writes decompressed data directly to disk without a running total or configurable size limit. There is no equivalent of Python\u0027s `zipfile` `max_size` parameter.\n\n**Fix:** track cumulative decompressed bytes and raise before writing if a limit is exceeded:\n\n```python\nMAX_EXTRACT_SIZE = 2 * 1024 ** 3  # 2 GB default, configurable\n\ntotal = 0\nfor chunk in decompressed_chunks:\n    total += len(chunk)\n    if total \u003e MAX_EXTRACT_SIZE:\n        raise py7zr.exceptions.DecompressionBombError(\n            f\u0027Extraction aborted: decompressed size exceeded {MAX_EXTRACT_SIZE} bytes\u0027\n        )\n    outfile.write(chunk)\n```\n\nTested on py7zr 0.22.0, Python 3.12, Ubuntu 22.04.",
  "id": "GHSA-gjrg-mpp7-g774",
  "modified": "2026-06-19T21:16:29Z",
  "published": "2026-06-19T21:16:29Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/miurahr/py7zr/security/advisories/GHSA-gjrg-mpp7-g774"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/miurahr/py7zr"
    },
    {
      "type": "WEB",
      "url": "https://github.com/miurahr/py7zr/releases/tag/v1.1.3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "py7zr: Decompression bomb (zip bomb) denial of service via unchecked extraction size"
}

PYSEC-2026-2972

Vulnerability from pysec - Published: 2026-07-13 15:46 - Updated: 2026-07-13 16:05

Details

py7zr's Worker.decompress() extracts archive entries without tracking total decompressed size. A crafted .7z file can exhaust disk or memory before the extraction completes.

Measured: 15.6 KB archive → 100 MB output (6,556:1 ratio).

Proof of concept:

import py7zr, tempfile, os

# create bomb: compress 100MB of zeros into ~15KB
bomb_path = tempfile.mktemp(suffix='.7z')
with py7zr.SevenZipFile(bomb_path, 'w') as z:
    import io
    z.writef(io.BytesIO(b'\x00' * 100 * 1024 * 1024), 'bomb.bin')

print(f'archive size: {os.path.getsize(bomb_path):,} bytes')

# extract — no size check
with py7zr.SevenZipFile(bomb_path, 'r') as z:
    z.extractall(path=tempfile.mkdtemp())

print('extracted 100 MB from ~15 KB archive')

Fix: track cumulative decompressed bytes and raise before writing if a limit is exceeded:

MAX_EXTRACT_SIZE = 2 * 1024 ** 3  # 2 GB default, configurable

total = 0
for chunk in decompressed_chunks:
    total += len(chunk)
    if total > MAX_EXTRACT_SIZE:
        raise py7zr.exceptions.DecompressionBombError(
            f'Extraction aborted: decompressed size exceeded {MAX_EXTRACT_SIZE} bytes'
        )
    outfile.write(chunk)

Tested on py7zr 0.22.0, Python 3.12, Ubuntu 22.04.

Severity

6.9 (Medium)


                  
                    CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Impacted products

Name	purl
py7zr	pkg:pypi/py7zr

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "py7zr",
        "purl": "pkg:pypi/py7zr"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.0.3",
        "0.0.4",
        "0.0.5",
        "0.0.6",
        "0.0.7",
        "0.0.8",
        "0.1.0",
        "0.1.1",
        "0.1.2",
        "0.1.3",
        "0.1.4",
        "0.1.5",
        "0.1.6",
        "0.10.0",
        "0.10.0a1",
        "0.10.0a2",
        "0.10.0a3",
        "0.10.0a4",
        "0.10.0a5",
        "0.10.0a6",
        "0.10.0b1",
        "0.10.0b3",
        "0.10.1",
        "0.10.2",
        "0.11.0",
        "0.11.0a1",
        "0.11.0b1",
        "0.11.0b2",
        "0.11.0b3",
        "0.11.1",
        "0.11.2",
        "0.11.3",
        "0.12.0",
        "0.13.0",
        "0.13.1",
        "0.14.0",
        "0.14.1",
        "0.15.0",
        "0.15.1",
        "0.15.2",
        "0.16.0",
        "0.16.1",
        "0.16.2",
        "0.16.3",
        "0.16.4",
        "0.17.0",
        "0.17.1",
        "0.17.2",
        "0.17.3",
        "0.17.4",
        "0.18.0",
        "0.18.1",
        "0.18.10",
        "0.18.11",
        "0.18.12",
        "0.18.3",
        "0.18.4",
        "0.18.5",
        "0.18.6",
        "0.18.7",
        "0.18.9",
        "0.19.0",
        "0.19.1",
        "0.19.2",
        "0.2.0",
        "0.20.0",
        "0.20.1",
        "0.20.2",
        "0.20.4",
        "0.20.5",
        "0.20.6",
        "0.20.7",
        "0.20.8",
        "0.21.0",
        "0.21.1",
        "0.22.0",
        "0.3",
        "0.3.1",
        "0.3.2",
        "0.3.3",
        "0.3.4",
        "0.3.5",
        "0.4",
        "0.4.1",
        "0.4.3",
        "0.4.4",
        "0.4a1",
        "0.4a2",
        "0.4b1",
        "0.5",
        "0.5.2",
        "0.5.3",
        "0.5.4",
        "0.5.5",
        "0.5a3",
        "0.5a4",
        "0.5b1",
        "0.5b2",
        "0.5b3",
        "0.5b4",
        "0.5b5",
        "0.5b6",
        "0.5rc2",
        "0.5rc3",
        "0.6",
        "0.6a1",
        "0.6a2",
        "0.6b1",
        "0.6b2",
        "0.6b3",
        "0.6b4",
        "0.6b5",
        "0.6b6",
        "0.6b7",
        "0.6b8",
        "0.6rc0",
        "0.7.0",
        "0.7.0b1",
        "0.7.0b2",
        "0.7.0b3",
        "0.7.1",
        "0.7.2",
        "0.7.3",
        "0.7.4",
        "0.8.0",
        "0.8.0a1",
        "0.8.0a2",
        "0.8.0a3",
        "0.8.0b1",
        "0.8.0b2",
        "0.8.0b3",
        "0.8.0b4",
        "0.8.0b5",
        "0.8.0b6",
        "0.8.0b7",
        "0.8.0b8",
        "0.8.1",
        "0.8.2",
        "0.8.3",
        "0.8.4",
        "0.8.5",
        "0.9.0",
        "0.9.0a1",
        "0.9.0a2",
        "0.9.0b1",
        "0.9.0b2",
        "0.9.0b3",
        "0.9.1",
        "0.9.10",
        "0.9.2",
        "0.9.3",
        "0.9.4",
        "0.9.5",
        "0.9.7",
        "0.9.8",
        "0.9.9",
        "1.0.0",
        "1.0.0rc1",
        "1.0.0rc2",
        "1.0.0rc3",
        "1.1.0",
        "1.1.0rc2",
        "1.1.0rc4",
        "1.1.2"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55195",
    "GHSA-gjrg-mpp7-g774"
  ],
  "details": "py7zr\u0027s `Worker.decompress()` extracts archive entries without tracking total decompressed size. A crafted `.7z` file can exhaust disk or memory before the extraction completes.\n\nMeasured: 15.6 KB archive \u2192 100 MB output (6,556:1 ratio).\n\n**Proof of concept:**\n\n```python\nimport py7zr, tempfile, os\n\n# create bomb: compress 100MB of zeros into ~15KB\nbomb_path = tempfile.mktemp(suffix=\u0027.7z\u0027)\nwith py7zr.SevenZipFile(bomb_path, \u0027w\u0027) as z:\n    import io\n    z.writef(io.BytesIO(b\u0027\\x00\u0027 * 100 * 1024 * 1024), \u0027bomb.bin\u0027)\n\nprint(f\u0027archive size: {os.path.getsize(bomb_path):,} bytes\u0027)\n\n# extract \u2014 no size check\nwith py7zr.SevenZipFile(bomb_path, \u0027r\u0027) as z:\n    z.extractall(path=tempfile.mkdtemp())\n\nprint(\u0027extracted 100 MB from ~15 KB archive\u0027)\n```\n\n**Root cause:** `Worker.decompress()` in `py7zr/worker.py` writes decompressed data directly to disk without a running total or configurable size limit. There is no equivalent of Python\u0027s `zipfile` `max_size` parameter.\n\n**Fix:** track cumulative decompressed bytes and raise before writing if a limit is exceeded:\n\n```python\nMAX_EXTRACT_SIZE = 2 * 1024 ** 3  # 2 GB default, configurable\n\ntotal = 0\nfor chunk in decompressed_chunks:\n    total += len(chunk)\n    if total \u003e MAX_EXTRACT_SIZE:\n        raise py7zr.exceptions.DecompressionBombError(\n            f\u0027Extraction aborted: decompressed size exceeded {MAX_EXTRACT_SIZE} bytes\u0027\n        )\n    outfile.write(chunk)\n```\n\nTested on py7zr 0.22.0, Python 3.12, Ubuntu 22.04.",
  "id": "PYSEC-2026-2972",
  "modified": "2026-07-13T16:05:50.259973Z",
  "published": "2026-07-13T15:46:22.219693Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/miurahr/py7zr/security/advisories/GHSA-gjrg-mpp7-g774"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/miurahr/py7zr"
    },
    {
      "type": "WEB",
      "url": "https://github.com/miurahr/py7zr/releases/tag/v1.1.3"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/py7zr"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-gjrg-mpp7-g774"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55195"
    }
  ],
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "py7zr: Decompression bomb (zip bomb) denial of service via unchecked extraction size"
}

ubuntu-cve-2026-55195

Vulnerability from osv_ubuntu

Published

2026-07-08 21:16

Modified

2026-07-15 17:53

Summary

Details

Severity

8.7 (High)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-55195	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-55195	REPORT
	https://github.com/miurahr/py7zr/commit/28faf107b…	REPORT
	https://github.com/miurahr/py7zr/releases/tag/v1.1.3	REPORT
	https://github.com/miurahr/py7zr/security/advisor…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-py7zr",
            "binary_version": "0.11.3+dfsg-4ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "py7zr",
        "purl": "pkg:deb/ubuntu/py7zr@0.11.3+dfsg-4ubuntu0.1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.11.3+dfsg-1",
        "0.11.3+dfsg-1ubuntu1",
        "0.11.3+dfsg-2",
        "0.11.3+dfsg-3",
        "0.11.3+dfsg-4",
        "0.11.3+dfsg-4ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-py7zr",
            "binary_version": "0.11.3+dfsg-8build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "py7zr",
        "purl": "pkg:deb/ubuntu/py7zr@0.11.3+dfsg-8build1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.11.3+dfsg-6",
        "0.11.3+dfsg-7",
        "0.11.3+dfsg-8",
        "0.11.3+dfsg-8build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-py7zr",
            "binary_version": "1.0.0+dfsg1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "py7zr",
        "purl": "pkg:deb/ubuntu/py7zr@1.0.0+dfsg1-1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.22.0+dfsg-1",
        "1.0.0+dfsg1-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-py7zr",
            "binary_version": "1.1.2+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "py7zr",
        "purl": "pkg:deb/ubuntu/py7zr@1.1.2+dfsg-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0.0+dfsg1-1",
        "1.0.0+dfsg1-3",
        "1.0.0+dfsg1-4",
        "1.0.0+dfsg1-5",
        "1.1.2+dfsg-1"
      ]
    }
  ],
  "aliases": [],
  "details": "py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, py7zr\u0027s Worker.decompress() extracted archive entries without tracking total decompressed size, allowing a crafted .7z file such as a 15.6 KB archive that expands to 100 MB to exhaust disk or memory before extraction completes. This issue is fixed in version 1.1.3.",
  "id": "UBUNTU-CVE-2026-55195",
  "modified": "2026-07-15T17:53:44Z",
  "published": "2026-07-08T21:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-55195"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-55195"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/miurahr/py7zr/commit/28faf107b64374fa5a02bfb93aa2024e281ca97b"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/miurahr/py7zr/releases/tag/v1.1.3"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/miurahr/py7zr/security/advisories/GHSA-gjrg-mpp7-g774"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-55195"
  ]
}

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.

Action not permitted

CVE-2026-55195 (GCVE-0-2026-55195)

FKIE_CVE-2026-55195

GHSA-GJRG-MPP7-G774

PYSEC-2026-2972

ubuntu-cve-2026-55195

Vulnerability from osv_ubuntu

Tags

Sightings

Nomenclature

Related by attack behaviour