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
Elevated
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 8.1Exploit: Elevated riskExposed services: Not assessed

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
8.1HIGHmedium confidence
EG Risk
67
EG Risk 67/100

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%
EPSS PROB
0.7%
EPSS %ILE
51st
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 / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
nltk3.10.0-1 ... 3.9.3-1 (12 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
nltk3.10.0-1 ... 3.9.3-1 (9 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
nltk3.10.0-1 ... 3.9.3-1 (6 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
nltk3.9.1-2, 3.9.2-1, 3.9.3-1
  • every version up to 3.10.0-1: fixed in 3.10.0-1
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
nltk0.8 ... 3.9b1 (64 versions)
  • every version through 3.9.2: no fix on record
  • every version up to 3.9.4: fixed in 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 4× in last 7d / 24× 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 145 total refreshes for this CVE.

  1. 2026-10-04 23:22 UTCEPSS rescore
  2. 2026-10-03 14:25 UTCEPSS rescore
  3. 2026-10-01 19:49 UTCEPSS rescore
  4. 2026-09-30 15:03 UTCEPSS rescore
  5. 2026-09-28 13:51 UTCEPSS rescore
  6. 2026-09-27 13:48 UTCEPSS rescore
  7. 2026-09-26 15:58 UTCEPSS rescore
  8. 2026-09-26 00:26 UTCEPSS rescore
  9. 2026-09-21 20:18 UTCOSV refresh
  10. 2026-09-20 20:15 UTCEPSS rescore
  11. 2026-09-18 19:28 UTCEPSS rescore
  12. 2026-09-18 19:28 UTCEPSS rescore
  13. 2026-09-17 19:30 UTCEPSS rescore
  14. 2026-09-16 14:08 UTCEPSS rescore
  15. 2026-09-16 05:15 UTCEPSS rescore
  16. 2026-09-15 03:11 UTCEPSS rescore
  17. 2026-09-13 16:47 UTCEPSS rescore
  18. 2026-09-12 15:01 UTCEPSS rescore
  19. 2026-09-11 14:52 UTCEPSS rescore
  20. 2026-09-10 09:34 UTCEPSS rescore
  21. 2026-09-08 22:00 UTCEPSS rescore
  22. 2026-09-07 16:01 UTCEPSS rescore
  23. 2026-09-06 13:47 UTCEPSS rescore
  24. 2026-09-06 13:47 UTCEPSS rescore
  25. 2026-09-04 05:06 UTCEPSS rescore
Show 75 more
  1. 2026-09-02 16:38 UTCOSV refresh
  2. 2026-09-02 14:11 UTCEPSS rescore
  3. 2026-09-01 13:53 UTCEPSS rescore
  4. 2026-09-01 04:39 UTCEPSS rescore
  5. 2026-09-01 04:39 UTCEPSS rescore
  6. 2026-08-30 19:17 UTCEPSS rescore
  7. 2026-08-30 01:22 UTCEPSS rescore
  8. 2026-08-28 21:41 UTCEPSS rescore
  9. 2026-08-27 14:25 UTCEPSS rescore
  10. 2026-08-26 14:46 UTCEPSS rescore
  11. 2026-08-25 13:49 UTCEPSS rescore
  12. 2026-08-24 14:17 UTCEPSS rescore
  13. 2026-08-23 00:19 UTCEPSS rescore
  14. 2026-08-21 23:49 UTCEPSS rescore
  15. 2026-08-20 22:55 UTCEPSS rescore
  16. 2026-08-20 22:55 UTCEPSS rescore
  17. 2026-08-19 17:03 UTCEPSS rescore
  18. 2026-08-18 13:48 UTCEPSS rescore
  19. 2026-08-17 13:47 UTCEPSS rescore
  20. 2026-08-16 14:56 UTCEPSS rescore
  21. 2026-08-16 10:59 UTCEG score recompute
  22. 2026-08-16 10:59 UTCVendor advisory
  23. 2026-08-16 10:59 UTCGHSA enrichment
  24. 2026-08-16 02:14 UTCEPSS rescore
  25. 2026-08-15 01:30 UTCEPSS rescore
  26. 2026-08-14 19:59 UTCVendor advisory
  27. 2026-08-14 19:59 UTCGHSA enrichment
  28. 2026-08-14 07:09 UTCEG score recompute
  29. 2026-08-14 07:09 UTCVendor advisory
  30. 2026-08-14 07:09 UTCGHSA enrichment
  31. 2026-08-13 22:00 UTCEPSS rescore
  32. 2026-08-12 21:49 UTCEG score recompute
  33. 2026-08-12 21:49 UTCVendor advisory
  34. 2026-08-12 21:49 UTCGHSA enrichment
  35. 2026-08-12 13:50 UTCEPSS rescore
  36. 2026-08-11 21:22 UTCEG score recompute
  37. 2026-08-11 21:22 UTCVendor advisory
  38. 2026-08-11 21:22 UTCGHSA enrichment
  39. 2026-08-11 04:22 UTCEG score recompute
  40. 2026-08-11 04:22 UTCVendor advisory
  41. 2026-08-11 04:22 UTCGHSA enrichment
  42. 2026-08-11 00:00 UTCEPSS rescore
  43. 2026-08-10 08:22 UTCVendor advisory
  44. 2026-08-10 08:22 UTCGHSA enrichment
  45. 2026-08-09 19:33 UTCEG score recompute
  46. 2026-08-09 19:33 UTCVendor advisory
  47. 2026-08-09 19:33 UTCGHSA enrichment
  48. 2026-08-09 13:46 UTCEPSS rescore
  49. 2026-08-09 06:43 UTCEG score recompute
  50. 2026-08-09 06:43 UTCVendor advisory
  51. 2026-08-09 06:43 UTCGHSA enrichment
  52. 2026-08-08 16:37 UTCEPSS rescore
  53. 2026-08-08 06:02 UTCVendor advisory
  54. 2026-08-08 06:02 UTCGHSA enrichment
  55. 2026-08-07 17:12 UTCEG score recompute
  56. 2026-08-07 17:12 UTCVendor advisory
  57. 2026-08-07 17:12 UTCGHSA enrichment
  58. 2026-08-06 19:15 UTCEG score recompute
  59. 2026-08-06 19:15 UTCVendor advisory
  60. 2026-08-06 19:15 UTCGHSA enrichment
  61. 2026-08-06 13:46 UTCEPSS rescore
  62. 2026-08-06 01:25 UTCEG score recompute
  63. 2026-08-06 01:25 UTCVendor advisory
  64. 2026-08-06 01:25 UTCGHSA enrichment
  65. 2026-08-05 19:17 UTCEPSS rescore
  66. 2026-08-04 15:10 UTCEPSS rescore
  67. 2026-08-04 10:38 UTCEPSS rescore
  68. 2026-08-04 00:33 UTCEG score recompute
  69. 2026-08-04 00:33 UTCVendor advisory
  70. 2026-08-04 00:33 UTCGHSA enrichment
  71. 2026-08-03 10:36 UTCEPSS rescore
  72. 2026-08-02 16:08 UTCEG score recompute
  73. 2026-08-02 16:08 UTCVendor advisory
  74. 2026-08-02 16:08 UTCGHSA enrichment
  75. 2026-08-02 02:27 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 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 0.7% probability of exploitation in the next 30 days (51st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-33236?
CVE-2026-33236 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-33236?
A fix for CVE-2026-33236 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-33236 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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