CVE-2026-33236

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-03-19. a secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this weekElevated
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.1Exploit: Elevated riskExposed: 0

A fix is available — apply it.

NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. In versions 3.9.3 and prior, the NLTK downloader does not validate the subdir and id attributes when processing remote XML index files. Attackers can control a remote XML index server to provide malicious values containing path traversal sequences (such as ../), which can lead to arbitrary directory creation, arbitrary file creation, and arbitrary file overwrite. Commit 89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a patches the issue.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
67(Attend)
EG Risk 67/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity81% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
45%
KEV
Not listed

Published

March 20, 2026

Last Modified

July 21, 2026

Advisory Details (7)

Auto-updated Jun 30, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github, redhat.
redhat
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33236.json
redhat

2449824 – (CVE-2026-33236) CVE-2026-33236 nltk: NLTK: Arbitrary file overwrite and creation via path traversal in XML index files

https://bugzilla.redhat.com/show_bug.cgi?id=2449824
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-33236
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:19712
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:10184
github Patch Available🟡 PoC Available

Downloader Path Traversal Vulnerability (AFO) - Arbitrary File Overwrite · Advisory · nltk/nltk · GitHub

https://github.com/nltk/nltk/security/advisories/GHSA-469j-vmhf-r6v7
github_commit Patch Available

commit 89fe2ec2c6ba (nltk/nltk)

Patch available: nltk/nltk v3.10.0-rc1 (contains commit 89fe2ec2c6ba)

https://github.com/nltk/nltk/commit/89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a

Vendor Advisories for CVE-2026-33236(4)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(6)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhoai/odh-ta-lmes-job-rhel9:17830911752026-07-21redhat
redhatrhoai/odh-trustyai-nemo-guardrails-server-rhel9:17824716062026-07-09redhat
ubuntupython3-nltk (3.4.5-2ubuntu0.1~esm4) @ focal2026-06-30ubuntu
redhatrhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9:17782630542026-05-20redhat
redhatrhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9:17763191852026-04-23redhat
pipnltk—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
nltk3.10.0-1 ... 3.9.3-1 (12 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
nltk3.10.0-1 ... 3.9.3-1 (8 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
nltk3.10.0-1, 3.10.1-1, 3.9.1-2, 3.9.2-1, 3.9.3-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
nltk3.9.1-2, 3.9.2-1, 3.9.3-13.10.0-1—
PyPI(1)
PackageVulnerable rangeFixed inDependents
nltk0.8 ... 3.9b1 (64 versions)3.9.4—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 13× in last 7d / 75× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 106 total refreshes for this CVE.

  1. 2026-08-20 22:55 UTCEPSS rescore
  2. 2026-08-20 22:55 UTCEPSS rescore
  3. 2026-08-19 17:03 UTCEPSS rescore
  4. 2026-08-18 13:48 UTCEPSS rescore
  5. 2026-08-17 13:47 UTCEPSS rescore
  6. 2026-08-16 14:56 UTCEPSS rescore
  7. 2026-08-16 10:59 UTCEG score recompute
  8. 2026-08-16 10:59 UTCVendor advisory
  9. 2026-08-16 10:59 UTCGHSA enrichment
  10. 2026-08-16 02:14 UTCEPSS rescore
  11. 2026-08-15 01:30 UTCEPSS rescore
  12. 2026-08-14 19:59 UTCVendor advisory
  13. 2026-08-14 19:59 UTCGHSA enrichment
  14. 2026-08-14 07:09 UTCEG score recompute
  15. 2026-08-14 07:09 UTCVendor advisory
  16. 2026-08-14 07:09 UTCGHSA enrichment
  17. 2026-08-13 22:00 UTCEPSS rescore
  18. 2026-08-12 21:49 UTCEG score recompute
  19. 2026-08-12 21:49 UTCVendor advisory
  20. 2026-08-12 21:49 UTCGHSA enrichment
  21. 2026-08-12 13:50 UTCEPSS rescore
  22. 2026-08-11 21:22 UTCEG score recompute
  23. 2026-08-11 21:22 UTCVendor advisory
  24. 2026-08-11 21:22 UTCGHSA enrichment
  25. 2026-08-11 04:22 UTCEG score recompute
Show 75 more
  1. 2026-08-11 04:22 UTCVendor advisory
  2. 2026-08-11 04:22 UTCGHSA enrichment
  3. 2026-08-11 00:00 UTCEPSS rescore
  4. 2026-08-10 08:22 UTCVendor advisory
  5. 2026-08-10 08:22 UTCGHSA enrichment
  6. 2026-08-09 19:33 UTCEG score recompute
  7. 2026-08-09 19:33 UTCVendor advisory
  8. 2026-08-09 19:33 UTCGHSA enrichment
  9. 2026-08-09 13:46 UTCEPSS rescore
  10. 2026-08-09 06:43 UTCEG score recompute
  11. 2026-08-09 06:43 UTCVendor advisory
  12. 2026-08-09 06:43 UTCGHSA enrichment
  13. 2026-08-08 16:37 UTCEPSS rescore
  14. 2026-08-08 06:02 UTCVendor advisory
  15. 2026-08-08 06:02 UTCGHSA enrichment
  16. 2026-08-07 17:12 UTCEG score recompute
  17. 2026-08-07 17:12 UTCVendor advisory
  18. 2026-08-07 17:12 UTCGHSA enrichment
  19. 2026-08-06 19:15 UTCEG score recompute
  20. 2026-08-06 19:15 UTCVendor advisory
  21. 2026-08-06 19:15 UTCGHSA enrichment
  22. 2026-08-06 13:46 UTCEPSS rescore
  23. 2026-08-06 01:25 UTCEG score recompute
  24. 2026-08-06 01:25 UTCVendor advisory
  25. 2026-08-06 01:25 UTCGHSA enrichment
  26. 2026-08-05 19:17 UTCEPSS rescore
  27. 2026-08-04 15:10 UTCEPSS rescore
  28. 2026-08-04 10:38 UTCEPSS rescore
  29. 2026-08-04 00:33 UTCEG score recompute
  30. 2026-08-04 00:33 UTCVendor advisory
  31. 2026-08-04 00:33 UTCGHSA enrichment
  32. 2026-08-03 10:36 UTCEPSS rescore
  33. 2026-08-02 16:08 UTCEG score recompute
  34. 2026-08-02 16:08 UTCVendor advisory
  35. 2026-08-02 16:08 UTCGHSA enrichment
  36. 2026-08-02 02:27 UTCEPSS rescore
  37. 2026-08-01 04:16 UTCEPSS rescore
  38. 2026-07-30 16:28 UTCEPSS rescore
  39. 2026-07-30 01:30 UTCEPSS rescore
  40. 2026-07-27 14:13 UTCEPSS rescore
  41. 2026-07-26 14:54 UTCEPSS rescore
  42. 2026-07-26 14:54 UTCEPSS rescore
  43. 2026-07-25 14:18 UTCEPSS rescore
  44. 2026-07-25 14:18 UTCEPSS rescore
  45. 2026-07-24 14:17 UTCEPSS rescore
  46. 2026-07-24 14:17 UTCEPSS rescore
  47. 2026-07-23 14:18 UTCEPSS rescore
  48. 2026-07-23 14:18 UTCEPSS rescore
  49. 2026-07-23 03:09 UTCEG score recompute
  50. 2026-07-22 14:08 UTCEPSS rescore
  51. 2026-07-21 15:24 UTCEPSS rescore
  52. 2026-07-20 17:08 UTCEPSS rescore
  53. 2026-07-19 14:31 UTCEPSS rescore
  54. 2026-07-19 02:29 UTCEPSS rescore
  55. 2026-07-18 10:04 UTCEPSS rescore
  56. 2026-07-18 06:59 UTCOSV refresh
  57. 2026-07-16 17:03 UTCEPSS rescore
  58. 2026-07-15 16:57 UTCEPSS rescore
  59. 2026-07-15 16:57 UTCEPSS rescore
  60. 2026-07-15 02:00 UTCEPSS rescore
  61. 2026-07-15 02:00 UTCEPSS rescore
  62. 2026-07-13 22:30 UTCEPSS rescore
  63. 2026-07-13 06:13 UTCEPSS rescore
  64. 2026-07-13 06:13 UTCEPSS rescore
  65. 2026-07-12 05:46 UTCEPSS rescore
  66. 2026-07-11 08:27 UTCEPSS rescore
  67. 2026-07-09 19:10 UTCEPSS rescore
  68. 2026-07-08 15:15 UTCEPSS rescore
  69. 2026-07-07 13:46 UTCEPSS rescore
  70. 2026-07-06 16:27 UTCEPSS rescore
  71. 2026-07-06 16:27 UTCEPSS rescore
  72. 2026-07-06 02:23 UTCEPSS rescore
  73. 2026-07-06 02:23 UTCEPSS rescore
  74. 2026-07-05 02:30 UTCEPSS rescore
  75. 2026-07-04 06:31 UTCEPSS rescore

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-33236?
CVE-2026-33236 is a high vulnerability published on March 20, 2026. NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. In versions 3.9.3 and prior, the NLTK downloader does not validate the subdir and id attributes when processing remote XML index…
When was CVE-2026-33236 disclosed?
CVE-2026-33236 was first published in the National Vulnerability Database on March 20, 2026, with the most recent update on July 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33236 actively exploited?
CVE-2026-33236 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 55.0% of all scored CVEs.
What is the CVSS score of CVE-2026-33236?
CVE-2026-33236 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-33236?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33236, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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