CVE-2026-12243
描述
NLTK version 3.9.4 is vulnerable to a path traversal attack due to an incomplete fix for GitHub Issue #3504. The `_UNSAFE_NO_PROTOCOL_RE` regex in `nltk/data.py` checks for literal `../` sequences but fails to account for percent-encoded traversal sequences such as `..%2f`. The `url2pathname()` function decodes these sequences after the validation step, allowing an attacker to bypass the protection. This vulnerability enables an attacker to read arbitrary files accessible to the Python process by controlling the resource name parameter passed to `nltk.data.load()` or `nltk.data.find()`. The issue affects applications that rely on NLTK for resource loading, including NLP web applications, Jupyter notebooks, and CLI tools. The default `pathsec.ENFORCE=False` setting exacerbates the impact by not blocking the file read at the `open()` stage.
如何修補 CVE-2026-12243
目前尚未發布修補版本。可考慮移除受影響套件,或參考下方連結中的上游建議。
- —未列出修補版本
- —未列出修補版本
CVE-2026-12243 正在被利用嗎?
低 — EPSS 為 0.5%,目前沒有觀察到大規模利用活動。
受影響套件(2)
- from 0
- from 0, <= 3.9.4
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |