Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
NLTK: URL-Encoded Path Traversal in nltk.data.load() Allows Arbitrary Local File Read
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L N N U H N N 7.5 .0056 43.9 —
AFFECTED
Product Versions Fixed
nltk < 3.10.0-rc1 – —
TIMELINE
Jun 12 Reserved by GitHub_M
Jun 22 EXPLOIT PUBLISHED — CVE-2026-54293 (nltk). Public exploit reference added.
Jun 22 Published (CNA: GitHub_M)
Jul 21 EXPLOIT PUBLISHED — CVE-2026-54293 (nltk). Public exploit reference added.
Description
NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. Prior to 3.10.0-rc1, nltk.data.load() in NLTK is vulnerable to path traversal via URL-encoded path separators and traversal segments when using the nltk: URL scheme. The unsafe-path regex check is performed before url2pathname() decodes the %xx sequences (a classic decode-after-check / TOCTOU-style flaw), allowing an attacker to bypass the protection documented in NLTK's SECURITY.md and read arbitrary files from the filesystem. While literal traversal strings such as ../../../etc/passwd are correctly blocked, encoded variants such as %2fetc%2fpasswd, %2e%2e%2f..., and ..%2f..%2f slip past the regex and are subsequently decoded into a real filesystem path. This vulnerability is fixed in 3.10.0-rc1.
Lifecycle
Complete event history — 4 events, chronological
| Date | Event | Detail |
|---|
| June 12, 2026 | Reserved | Reserved by GitHub_M |
| June 22, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-54293 (nltk). Public exploit reference added. |
| June 22, 2026 | Published | Published (CNA: GitHub_M) |
| July 21, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-54293 (nltk). Public exploit reference added. |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| nltk | nltk | — | < 3.10.0-rc1 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-54293 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.