CVE-2026-49854
Tornado has out-of-bounds memory access via C extension
描述
### Summary Tornado's optional native extension `tornado.speedups` implements `websocket_mask` without validating that the `mask` argument is exactly four bytes long. The C function reads four bytes from `mask` unconditionally, even when Python passes a shorter byte string. This can read beyond the provided buffer, exposing up to 3 bytes of uninitialized memory. The behavior is reachable from Tornado's XSRF token decoder when `xsrf_cookies=True` and the native extension is active. ### Mitigations This bug is fixed in Tornado 6.5.6. Prior to upgrading to this version, setting the environment variable TORNADO_EXTENSION=0 will disable the vulnerable code (at the expense of reducing websocket performance).
如何修補 CVE-2026-49854
要修補 CVE-2026-49854,請將受影響套件升級到下列已修補版本。
- —升級至 6.5.6 或更新版本
CVE-2026-49854 正在被利用嗎?
目前沒有被利用訊號。CVE-2026-49854 既不在 CISA KEV 也沒有最新的 EPSS 分數。
受影響套件(1)
- from 0, < 6.5.6
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 3.1 | LOW3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |