Upstream information
Description
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.SUSE information
Overall state of this security issue: Resolved
This issue is currently not rated by SUSE as it is not affecting the SUSE Enterprise products.
| CVSS detail | CNA (Huntr.dev) |
|---|---|
| Base Score | 3.7 |
| Vector | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality Impact | Low |
| Integrity Impact | None |
| Availability Impact | None |
| CVSSv3 Version | 3 |
List of released packages
| Product(s) | Fixed package version(s) | References |
|---|---|---|
| openSUSE Tumbleweed |
| Patchnames: openSUSE-Tumbleweed-2026-11510 |
SUSE Timeline for this CVE
CVE page created: Mon Aug 10 15:25:11 2026CVE page last modified: Fri Aug 14 11:27:31 2026