CVE-2026-15310

zipfile: bzip2/LZMA/Zstandard members decompress without a max_length bound, defeating chunked-read memory limits

Published Aug 25, 2026 CVSS 4.0 · 2.1 Low EPSS < 1% KEV · Not listed
Description
When decompressing crafted zip files using the bzip/LZMA/Zstandard

compressions, Python could use an attacker-controlled size to

pre-allocate memory, possibly resulting in memory exhaustion.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4827-1 python3.11 security update
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Python
Python cpython
Vendors & Products Python
Python cpython
Type Values Removed Values Added
Description When decompressing crafted zip files using the bzip/LZMA/Zstandard compressions, Python could use an attacker-controlled size to pre-allocate memory, possibly resulting in memory exhaustion.
Title zipfile: bzip2/LZMA/Zstandard members decompress without a max_length bound, defeating chunked-read memory limits
Weaknesses CWE-400
References
Metrics cvssV4_0

{'score': 2.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
PSF
Published
Updated
Nov 10, 2026, 12:40 PM
Reserved
Jul 9, 2026, 5:39 PM
Status
Awaiting Analysis
Published
Aug 25, 2026, 3:16 PM
Modified
Nov 10, 2026, 1:18 PM