CVE-2026-9669
Received
Received - Intake
BZ2Decompressor Use-After-Free in Python
Publication date: 2026-06-08
Last updated on: 2026-06-09
Assigner: Python Software Foundation
Description
Description
bz2.BZ2Decompressor objects could be reused after a decompression error. If an application caught the resulting OSError and retried with the same decompressor, crafted input could cause the decompressor to resume from an invalid internal state and perform out-of-bounds writes to a stack buffer. This could crash the process when processing untrusted data.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| python | cpython | From 3.16.0 (exc) |
| python | cpython | 3.10 |
| python | cpython | 3.11 |
| python | cpython | 3.12 |
| python | cpython | 3.13 |
| python | cpython | 3.14 |
| python | cpython | 3.15 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-121 | A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). |