Upstream information

CVE-2026-12372 at MITRE

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 v3 Scores
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
SUSE Bugzilla entry: 1274590 [IN_PROGRESS]

No SUSE Security Announcements cross referenced.

List of released packages

Product(s) Fixed package version(s) References
SUSE Package Hub 15 SP7
  • python311-nltk >= 3.10.3-bp157.3.24.1
 Patchnames:
openSUSE-2026-359
openSUSE Tumbleweed
  • python313-nltk >= 3.10.2-1.1
  • python314-nltk >= 3.10.2-1.1
 Patchnames:
openSUSE-Tumbleweed-2026-11510

Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Package Hub 15 SP7 python-nltk Released

SUSE Timeline for this CVE

CVE page created: Mon Aug 10 15:25:11 2026
CVE page last modified: Mon Oct 26 17:32:52 2026