NLTK network URL validation permits SSRF to RFC 6598 shared-address-space hosts

THẤP 3.7CVE-2026-12372 · GHSA-2jhm-w3mp-jcwr · PYSEC-2026-3955 · Công bố 09/08/2026 · cập nhật 23/10/2026

Tóm tắt nhanh

CVE-2026-12372 là lỗ hổng mức THẤP (CVSS 3.7) ảnh hưởng nltk, nltk (nltk).
Xác suất bị khai thác trong 30 ngày tới (EPSS): 0.26%, cao hơn 17.7% các lỗ hổng khác.
Cách xử lý: cập nhật lên 3.10.0 hoặc mới hơn.

Gói / sản phẩm	Phiên bản bị ảnh hưởng	Phiên bản đã vá
nltk PyPI	`≤ 3.9.4< 3.10.0`	`3.10.0`
nltk nltk	`= 3.9.4`	Chưa có bản vá

Mô tả

A Server-Side Request Forgery (SSRF) vulnerability exists in nltk/nltk versions 3.9.4 and the current develop branch. The nltk.pathsec.validate_network_url() function, intended to prevent SSRF by rejecting internal network addresses, fails to reject IPs in the RFC 6598 shared address space (100.64.0.0/10). This occurs because Python's ipaddress module does not classify such addresses as is_private or is_global, and the current guard only checks is_private and a few explicit categories. An attacker who can influence a URL passed to NLTK's network-loading helpers can exploit this vulnerability to make a strict-mode application send requests to shared-address-space hosts, potentially exposing non-public infrastructure reachable from the application host. The impact is limited to SSRF-style confidentiality exposure, with no code execution claimed.

Mô tả của NVD

A Server-Side Request Forgery (SSRF) vulnerability exists in nltk/nltk versions 3.9.4 and the current develop branch. The `nltk.pathsec.validate_network_url()` function, intended to prevent SSRF by rejecting internal network addresses, fails to reject IPs in the RFC 6598 shared address space (`100.64.0.0/10`). This occurs because Python's `ipaddress` module does not classify such addresses as `is_private` or `is_global`, and the current guard only checks `is_private` and a few explicit categories. An attacker who can influence a URL passed to NLTK's network-loading helpers can exploit this vulnerability to make a strict-mode application send requests to shared-address-space hosts, potentially exposing non-public infrastructure reachable from the application host. The impact is limited to SSRF-style confidentiality exposure, with no code execution claimed.