High
py7zr: Decompression bomb (zip bomb) denial of service via unchecked extraction size
Type: advisorySources: OSV
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-55195
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 01:25 UTC · Revision 1
Source evidence
py7zr: Decompression bomb (zip bomb) denial of service via unchecked extraction size
core-osv · Original sourcePublished 8 Jul 2026, 20:30 UTC
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.
osv:CVE-2026-55195
Complete source record
{
"id": "1b3c1341b483b039f10eb4267c3fd3c6acfbf60d7f52d01b6382ddac83d5f57f",
"url": "https://osv.dev/vulnerability/CVE-2026-55195",
"method": "structured",
"payload": {
"kind": "advisory",
"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.",
"evidence": "osv:CVE-2026-55195",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-55195",
"aliases": [
"CVE-2026-55195",
"GHSA-gjrg-mpp7-g774",
"PYSEC-2026-2972"
],
"metrics": [
{
"type": "CVSS_V4",
"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"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/miurahr/py7zr",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "e278bc05cc937ecd1ee62bc6a058db3a21e66614"
},
{
"fixed": "28faf107b64374fa5a02bfb93aa2024e281ca97b"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "1.1.3"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"fixed": "28faf107b64374fa5a02bfb93aa2024e281ca97b"
}
],
"source": "REFERENCES_COMMIT"
},
{
"range": [
{
"fixed": "e278bc05cc937ecd1ee62bc6a058db3a21e66614"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v1.1.3"
}
]
}
}
],
"versions": [
"v1.1.2",
"v1.1.0",
"v1.1.0rc4",
"v1.1.0rc3",
"v1.1.0rc2",
"v1.0.0rc3",
"v1.0.0rc2",
"v1.0.0-rc1",
"v0.22.0",
"v0.21.1",
"v0.21.0",
"v0.20.8",
"v0.20.7",
"v0.20.6",
"v0.20.5",
"v0.20.4",
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"v0.18.0",
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"v0.17.1",
"v0.17.0",
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"v0.16.1",
"v0.16.0",
"v0.15.2",
"v0.15.1",
"v0.15.0",
"v0.14.1",
"v0.13.0",
"v0.14.0",
"v0.12.0",
"v0.11.3",
"v0.10.1",
"v0.11.2",
"v0.11.1",
"v0.11.0",
"v0.10.0a1",
"v0.9.2",
"v0.9.1",
"v0.9.0",
"v0.9.0b3",
"v0.9.0b2",
"v0.9.0b1",
"v0.9.0a2",
"v0.8.0",
"v0.9.0a1",
"v0.8.0b8",
"v0.8.0b7",
"v0.8.0b6",
"v0.8.0b5",
"v0.8.0b4",
"v0.8.0b3",
"v0.7.3",
"v0.8.0b2",
"v0.8.0b1",
"v0.8.0a3",
"v0.8.0a2",
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"v0.7.2",
"v0.7.1",
"v0.7.0",
"v0.7.0b3",
"v0.7.0b2",
"v0.7.0b1",
"v0.6",
"v0.6rc",
"v0.6b8",
"v0.6b7",
"v0.6b6",
"v0.6b5",
"v0.6b4",
"v0.6b3",
"v0.6b2",
"v0.6b1",
"v0.6a2",
"v0.6a1",
"v0.5b6",
"v0.5b5",
"v0.5b4",
"v0.5b3",
"v0.5b2",
"v0.5b1",
"v0.5a4",
"v0.5a3",
"v0.5a2",
"v0.5a1",
"v0.4b1",
"v0.4a2",
"v0.4a1",
"v0.3.5",
"v0.3.4",
"v0.3.3",
"v0.3.2",
"v0.3.1",
"v0.3",
"v0.2.0",
"v0.1.6",
"v0.1.5",
"v0.1.4",
"v0.1.3",
"v0.1.2",
"v0.1.1",
"v0.1.0",
"v0.0.8",
"v0.0.7",
"v0.0.6",
"v0.0.5",
"v0.0.4",
"v0.0.3",
"v0.0.2",
"v0.0.1"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55195.json"
}
}
],
"modified": "2026-10-28T02:30:24.943791538Z",
"provider": "osv",
"references": [
"https://github.com/miurahr/py7zr/releases/tag/v1.1.3",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55195.json",
"https://github.com/miurahr/py7zr/security/advisories/GHSA-gjrg-mpp7-g774",
"https://nvd.nist.gov/vuln/detail/CVE-2026-55195",
"https://github.com/miurahr/py7zr/commit/28faf107b64374fa5a02bfb93aa2024e281ca97b"
],
"provider_metadata": {
"cwe_ids": [
"CWE-409"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55195.json"
}
},
"related_cves": [
{
"value": "CVE-2026-55195",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 491627,
"published_at": "2026-07-08T20:30:58.654+00:00"
}