Описание
Security update for python-cbor2
This update for python-cbor2 fixes the following issues:
- CVE-2025-68131: CBORDecoder reuse across trust boundaries can lead to leak of shareable values from previous decode calls via attacker-controlled messages (bsc#1255783).
- CVE-2026-26209: uncontrolled recursion via crafted CBOR payloads can cause a denial of service (bsc#1260367).
Список пакетов
openSUSE Leap 16.0
Ссылки
- SUSE Security Ratings
- SUSE Bug 1255783
- SUSE Bug 1260367
- SUSE CVE CVE-2025-68131 page
- SUSE CVE CVE-2026-26209 page
Описание
cbor2 provides encoding and decoding for the Concise Binary Object Representation (CBOR) serialization format. Starting in version 3.0.0 and prior to version 5.8.0, whhen a CBORDecoder instance is reused across multiple decode operations, values marked with the shareable tag (28) persist in memory and can be accessed by subsequent CBOR messages using the sharedref tag (29). This allows an attacker-controlled message to read data from previously decoded messages if the decoder is reused across trust boundaries. Version 5.8.0 patches the issue.
Затронутые продукты
Ссылки
- CVE-2025-68131
- SUSE Bug 1255783
Описание
cbor2 provides encoding and decoding for the Concise Binary Object Representation (CBOR) serialization format. Versions prior to 5.9.0 are vulnerable to a Denial of Service (DoS) attack caused by uncontrolled recursion when decoding deeply nested CBOR structures. This vulnerability affects both the pure Python implementation and the C extension `_cbor2`. The C extension relies on Python's internal recursion limits `Py_EnterRecursiveCall` rather than a data-driven depth limit, meaning it still raises `RecursionError` and crashes the worker process when the limit is hit. While the library handles moderate nesting levels, it lacks a hard depth limit. An attacker can supply a crafted CBOR payload containing approximately 100,000 nested arrays `0x81`. When `cbor2.loads()` attempts to parse this, it hits the Python interpreter's maximum recursion depth or exhausts the stack, causing the process to crash with a `RecursionError`. Because the library does not enforce its own limits, it allows an external attacker to exhaust the host application's stack resource. In many web application servers (e.g., Gunicorn, Uvicorn) or task queues (Celery), an unhandled `RecursionError` terminates the worker process immediately. By sending a stream of these small (<100KB) malicious packets, an attacker can repeatedly crash worker processes, resulting in a complete Denial of Service for the application. Version 5.9.0 patches the issue.
Затронутые продукты
Ссылки
- CVE-2026-26209
- SUSE Bug 1260367