CVE-2026-78682 (GCVE-0-2026-78682)

Vulnerability from cvelistv5 – Published: 2026-08-25 01:30 – Updated: 2026-08-25 15:23
VLAI
Title
NLTK before 3.10.3 SSRF Protection Bypass via Proxy
Summary
NLTK before 3.10.3 contains a server-side request forgery vulnerability in nltk.pathsec.urlopen (and callers nltk.data.load, nltk.downloader.Downloader.index/download) when an HTTP proxy is configured. pathsec.urlopen validates the requested hostname locally, but proxy-handler inheritance disables the safe HTTP/HTTPS handlers so the actual fetch is performed by the proxy against a destination that is never re-validated. An attacker can supply a validated public URL that the proxy forwards to an internal loopback-only service, allowing disclosure of internal HTTP resources, loading of forged downloader indexes, and installation of attacker-chosen package content.
Severity
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-25 15:23 UTC
CWE
  • CWE-918 - Server-Side Request Forgery (SSRF)
Assigner
References
Impacted products
Vendor Product Version CPE status
nltk nltk Affected: 0 , < 3.10.3 (semver)
Unaffected: 3.10.3 (semver)
    cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:*
Create a notification for this product.
Date Public
2026-08-11 00:00
Credits
sondt99
Show details on NVD website
To clipboard 

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