GHSA-qg9p-xrhj-435m

Suggest an improvement
Source
https://github.com/advisories/GHSA-qg9p-xrhj-435m
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-qg9p-xrhj-435m/GHSA-qg9p-xrhj-435m.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-qg9p-xrhj-435m
Withdrawn
2026-09-02T15:38:15Z
Published
2026-08-22T15:31:03Z
Modified
2026-09-02T16:00:17Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
  • 6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L CVSS Calculator
Summary
Duplicate Advisory: nltk: SSRF Fail-Open in validate_network_url() via DNS Resolution Failure
Details

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-3gqm-fcw5-w839. This link is maintained to preserve external references.

Original Description

NLTK before 3.10.0 (affected versions <= 3.9.4) contains a server-side request forgery (SSRF) vulnerability in the validate_network_url() function in nltk/pathsec.py. The _resolve_hostname() helper catches OSError and ValueError during socket.getaddrinfo() and returns an empty list; when DNS resolution fails, the validation loop executes no IP checks and the function fails open, allowing urlopen() to proceed without validation. An attacker who can trigger DNS resolution failures or use DNS rebinding can bypass SSRF protections and reach restricted network resources, including cloud metadata endpoints (e.g., 169.254.169.254).

Database specific 
{
    "cwe_ids":  [
        "CWE-918"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-09-02T15:38:15Z",
    "nvd_published_at":  "2026-08-22T15:16:19Z",
    "severity":  "MODERATE"
}
References

Affected packages

PyPI / nltk

Package

Name
nltk
View open source insights on deps.dev
Purl
pkg:pypi/nltk

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Last Affected
3.9.4

Affected versions

2.*
2.0.1rc2-git
2.0b4
2.0b5
2.0b6
2.0b7
2.0b8
2.0b9
2.0.1rc1
2.0.1rc3
2.0.1rc4
2.0.1
2.0.2
2.0.3
2.0.4
2.0.5
0.*
0.8
0.9
0.9.3
0.9.4
0.9.5
0.9.6
0.9.7
0.9.8
0.9.9
3.*
3.0.0b1
3.0.0b2
3.0.0
3.0.1
3.0.2
3.0.3
3.0.4
3.0.5
3.1
3.2
3.2.1
3.2.2
3.2.3
3.2.4
3.2.5
3.3
3.4
3.4.1
3.4.2
3.4.3
3.4.4
3.4.5
3.5b1
3.5
3.6
3.6.1
3.6.2
3.6.3
3.6.4
3.6.5
3.6.6
3.6.7
3.7
3.8
3.8.1
3.9b1
3.9
3.9.1
3.9.2
3.9.3
3.9.4

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-qg9p-xrhj-435m/GHSA-qg9p-xrhj-435m.json"