UnratedFix available

DEBIAN-CVE-2026-55206

Type: advisorySource: OSV1 source record

py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, PackInfo._read() in archiveinfo.py used an O(n^2) cumulative sum pattern for attacker-controlled numstreams values parsed from archive headers, allowing a crafted .7z archive to cause excessive CPU consumption during SevenZipFile.init() before extraction. This issue is fixed in version 1.1.3.

Announced 8 Jul 2026Source revision 1

Original source ↗

DEBIAN-CVE-2026-55206

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:DEBIAN-CVE-2026-55206

py7zr

Source reference: /affected/0/package/name

Affected versions: 0.11.3+dfsg-5
Source reference: /affected/0/versions
0.11.3+dfsg-6
Source reference: /affected/0/versions
0.11.3+dfsg-7
Source reference: /affected/0/versions
0.11.3+dfsg-8
Source reference: /affected/0/versions
0.21.0+dfsg-1
Source reference: /affected/0/versions
0.21.0+dfsg-2
Source reference: /affected/0/versions
0.21.1+dfsg-1
Source reference: /affected/0/versions
0.22.0+dfsg-1
Source reference: /affected/0/versions
1.0.0+dfsg1-1
Source reference: /affected/0/versions
1.0.0+dfsg1-2
Source reference: /affected/0/versions
1.0.0+dfsg1-3
Source reference: /affected/0/versions
1.0.0+dfsg1-3~bpo13+1
Source reference: /affected/0/versions
1.0.0+dfsg1-4
Source reference: /affected/0/versions
1.0.0+dfsg1-5
Source reference: /affected/0/versions
1.1.0+dfsg-1~exp1
Source reference: /affected/0/versions
1.1.2+dfsg-1
Source reference: /affected/0/versions
1.1.2+dfsg-1~exp1
Source reference: /affected/0/versions
1.1.2+dfsg-2
Source reference: /affected/0/versions
1.1.2+really1.1.0+dfsg-1
Source reference: /affected/0/versions
1.1.2-1+really1.1.0+dfsg-1
Source reference: /affected/0/versions
1.1.2-1+really1.1.0+dfsg-2
Source reference: /affected/0/versions
1.1.3+dfsg-1
Source reference: /affected/0/versions
1.1.3+dfsg-2
Source reference: /affected/0/versions
1.1.3+dfsg-3
Source reference: /affected/0/versions
1.1.3+dfsg-4
Source reference: /affected/0/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

py7zr

Source reference: /affected/1/package/name

Affected versions: 0.22.0+dfsg-1
Source reference: /affected/1/versions
1.0.0+dfsg1-1
Source reference: /affected/1/versions
1.0.0+dfsg1-2
Source reference: /affected/1/versions
1.0.0+dfsg1-3
Source reference: /affected/1/versions
1.0.0+dfsg1-3~bpo13+1
Source reference: /affected/1/versions
1.0.0+dfsg1-4
Source reference: /affected/1/versions
1.0.0+dfsg1-5
Source reference: /affected/1/versions
1.1.0+dfsg-1~exp1
Source reference: /affected/1/versions
1.1.2+dfsg-1
Source reference: /affected/1/versions
1.1.2+dfsg-1~exp1
Source reference: /affected/1/versions
1.1.2+dfsg-2
Source reference: /affected/1/versions
1.1.2+really1.1.0+dfsg-1
Source reference: /affected/1/versions
1.1.2-1+really1.1.0+dfsg-1
Source reference: /affected/1/versions
1.1.2-1+really1.1.0+dfsg-2
Source reference: /affected/1/versions
1.1.3+dfsg-1
Source reference: /affected/1/versions
1.1.3+dfsg-2
Source reference: /affected/1/versions
1.1.3+dfsg-3
Source reference: /affected/1/versions
1.1.3+dfsg-4
Source reference: /affected/1/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

py7zr

Source reference: /affected/2/package/name

Affected versions: 0.22.0+dfsg-1
Source reference: /affected/2/versions
1.0.0+dfsg1-1
Source reference: /affected/2/versions
1.0.0+dfsg1-2
Source reference: /affected/2/versions
1.0.0+dfsg1-3
Source reference: /affected/2/versions
1.0.0+dfsg1-3~bpo13+1
Source reference: /affected/2/versions
1.0.0+dfsg1-4
Source reference: /affected/2/versions
1.0.0+dfsg1-5
Source reference: /affected/2/versions
1.1.0+dfsg-1~exp1
Source reference: /affected/2/versions
1.1.2+dfsg-1
Source reference: /affected/2/versions
1.1.2+dfsg-1~exp1
Source reference: /affected/2/versions
1.1.2+dfsg-2
Source reference: /affected/2/versions
1.1.2+really1.1.0+dfsg-1
Source reference: /affected/2/versions
1.1.2-1+really1.1.0+dfsg-1
Source reference: /affected/2/versions
1.1.2-1+really1.1.0+dfsg-2
Source reference: /affected/2/versions
Fixed versions: 1.1.3+dfsg-1
Source reference: /affected/2/ranges
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "py7zr",
      "purl": "pkg:deb/debian/py7zr?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "0.11.3+dfsg-5",
      "0.11.3+dfsg-6",
      "0.11.3+dfsg-7",
      "0.11.3+dfsg-8",
      "0.21.0+dfsg-1",
      "0.21.0+dfsg-2",
      "0.21.1+dfsg-1",
      "0.22.0+dfsg-1",
      "1.0.0+dfsg1-1",
      "1.0.0+dfsg1-2",
      "1.0.0+dfsg1-3",
      "1.0.0+dfsg1-3~bpo13+1",
      "1.0.0+dfsg1-4",
      "1.0.0+dfsg1-5",
      "1.1.0+dfsg-1~exp1",
      "1.1.2+dfsg-1",
      "1.1.2+dfsg-1~exp1",
      "1.1.2+dfsg-2",
      "1.1.2+really1.1.0+dfsg-1",
      "1.1.2-1+really1.1.0+dfsg-1",
      "1.1.2-1+really1.1.0+dfsg-2",
      "1.1.3+dfsg-1",
      "1.1.3+dfsg-2",
      "1.1.3+dfsg-3",
      "1.1.3+dfsg-4"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55206.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "py7zr",
      "purl": "pkg:deb/debian/py7zr?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "0.22.0+dfsg-1",
      "1.0.0+dfsg1-1",
      "1.0.0+dfsg1-2",
      "1.0.0+dfsg1-3",
      "1.0.0+dfsg1-3~bpo13+1",
      "1.0.0+dfsg1-4",
      "1.0.0+dfsg1-5",
      "1.1.0+dfsg-1~exp1",
      "1.1.2+dfsg-1",
      "1.1.2+dfsg-1~exp1",
      "1.1.2+dfsg-2",
      "1.1.2+really1.1.0+dfsg-1",
      "1.1.2-1+really1.1.0+dfsg-1",
      "1.1.2-1+really1.1.0+dfsg-2",
      "1.1.3+dfsg-1",
      "1.1.3+dfsg-2",
      "1.1.3+dfsg-3",
      "1.1.3+dfsg-4"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55206.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "1.1.3+dfsg-1"
          }
        ]
      }
    ],
    "package": {
      "name": "py7zr",
      "purl": "pkg:deb/debian/py7zr?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "0.22.0+dfsg-1",
      "1.0.0+dfsg1-1",
      "1.0.0+dfsg1-2",
      "1.0.0+dfsg1-3",
      "1.0.0+dfsg1-3~bpo13+1",
      "1.0.0+dfsg1-4",
      "1.0.0+dfsg1-5",
      "1.1.0+dfsg-1~exp1",
      "1.1.2+dfsg-1",
      "1.1.2+dfsg-1~exp1",
      "1.1.2+dfsg-2",
      "1.1.2+really1.1.0+dfsg-1",
      "1.1.2-1+really1.1.0+dfsg-1",
      "1.1.2-1+really1.1.0+dfsg-2"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55206.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event: #57845 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 17:31:08 GMT
Publisher date: Wed, 08 Jul 2026 21:16:49 GMT

Read the original announcement