CVE-2026-81726

HIGHPre-NVD 7.07.0—
EchelonGraph scoreHIGH confidence

Score 7.0 from GitHub Security Advisory (severity: HIGH) published 2026-09-02. a secondary CVSS source baseline 7.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
7.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.0Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

NLTK through 3.10.3 contains a path traversal vulnerability in model-artifact APIs that bypass pathsec enforcement by using raw file operations on caller-controlled paths. Attackers can read or write files outside allowed sandbox roots through TransitionParser, AveragedPerceptron, PerceptronTagger, and maxent parameter APIs when pathsec is enabled.

CVSS v3
7.0
EG Score
7.0(high)
EG Risk
36(Track)
EG Risk 36/100SSVC: Track

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
Severity70% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
18%
KEV
Not listed

Published

August 27, 2026

Last Modified

August 31, 2026

Advisory Details (2)

Auto-updated Aug 27, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

NLTK through 3.10.3 Path Traversal via Model-Artifact APIs | Advisories | VulnCheck

https://www.vulncheck.com/advisories/nltk-through-3.10.3-path-traversal-via-model-artifact-apis
github Patch Available🟡 PoC Available

Model-artifact APIs bypass pathsec and touch files outside allowed roots · Advisory · nltk/nltk · GitHub

https://github.com/nltk/nltk/security/advisories/GHSA-8mgp-746c-j5xp

Vendor Advisories for CVE-2026-81726(1)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
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

(4 across 4 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
nltk3.10.0-1 ... 3.9.3-1 (9 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
nltk3.10.0-1 ... 3.9.3-1 (6 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
nltk3.10.0-1 ... 3.9.3-1 (6 versions)——
PyPI(1)
PackageVulnerable rangeFixed inDependents
nltk0.8 ... 3.9b1 (68 versions)3.10.3—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 25× in last 7d / 87× 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.

  1. 2026-09-19 05:22 UTCEG score recompute
  2. 2026-09-19 05:22 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 16:31 UTCGHSA enrichment
  5. 2026-09-18 03:37 UTCEG score recompute
  6. 2026-09-18 03:37 UTCGHSA enrichment
  7. 2026-09-17 14:47 UTCGHSA enrichment
  8. 2026-09-17 01:56 UTCEG score recompute
  9. 2026-09-17 01:56 UTCGHSA enrichment
  10. 2026-09-16 14:08 UTCEPSS rescore
  11. 2026-09-16 13:05 UTCEG score recompute
  12. 2026-09-16 13:05 UTCGHSA enrichment
  13. 2026-09-16 05:15 UTCEPSS rescore
  14. 2026-09-16 00:15 UTCGHSA enrichment
  15. 2026-09-15 11:23 UTCEG score recompute
  16. 2026-09-15 11:23 UTCGHSA enrichment
  17. 2026-09-15 03:12 UTCEPSS rescore
  18. 2026-09-15 03:12 UTCEPSS rescore
  19. 2026-09-14 22:33 UTCGHSA enrichment
  20. 2026-09-14 09:42 UTCGHSA enrichment
  21. 2026-09-13 20:50 UTCEG score recompute
  22. 2026-09-13 20:50 UTCGHSA enrichment
  23. 2026-09-13 07:59 UTCGHSA enrichment
  24. 2026-09-12 19:09 UTCEG score recompute
  25. 2026-09-12 19:09 UTCGHSA enrichment
Show 62 more
  1. 2026-09-12 06:19 UTCGHSA enrichment
  2. 2026-09-11 17:29 UTCEG score recompute
  3. 2026-09-11 17:29 UTCGHSA enrichment
  4. 2026-09-11 14:53 UTCEPSS rescore
  5. 2026-09-11 14:53 UTCEPSS rescore
  6. 2026-09-11 04:26 UTCGHSA enrichment
  7. 2026-09-10 15:35 UTCEG score recompute
  8. 2026-09-10 15:35 UTCGHSA enrichment
  9. 2026-09-10 02:40 UTCGHSA enrichment
  10. 2026-09-09 13:49 UTCGHSA enrichment
  11. 2026-09-09 00:40 UTCEG score recompute
  12. 2026-09-09 00:40 UTCGHSA enrichment
  13. 2026-09-08 22:01 UTCEPSS rescore
  14. 2026-09-08 07:25 UTCGHSA enrichment
  15. 2026-09-07 18:35 UTCEG score recompute
  16. 2026-09-07 18:35 UTCGHSA enrichment
  17. 2026-09-07 05:45 UTCGHSA enrichment
  18. 2026-09-06 16:55 UTCEG score recompute
  19. 2026-09-06 16:55 UTCGHSA enrichment
  20. 2026-09-06 13:48 UTCEPSS rescore
  21. 2026-09-06 04:05 UTCEG score recompute
  22. 2026-09-06 04:04 UTCGHSA enrichment
  23. 2026-09-05 15:31 UTCEPSS rescore
  24. 2026-09-05 15:14 UTCGHSA enrichment
  25. 2026-09-05 02:22 UTCEG score recompute
  26. 2026-09-05 02:22 UTCGHSA enrichment
  27. 2026-09-04 13:32 UTCEG score recompute
  28. 2026-09-04 13:32 UTCGHSA enrichment
  29. 2026-09-04 05:07 UTCEPSS rescore
  30. 2026-09-04 00:40 UTCGHSA enrichment
  31. 2026-09-03 11:50 UTCGHSA enrichment
  32. 2026-09-02 22:54 UTCEG score recompute
  33. 2026-09-02 22:54 UTCGHSA enrichment
  34. 2026-09-02 14:12 UTCEPSS rescore
  35. 2026-09-02 10:04 UTCGHSA enrichment
  36. 2026-09-01 21:11 UTCEG score recompute
  37. 2026-09-01 21:11 UTCGHSA enrichment
  38. 2026-09-01 13:54 UTCEPSS rescore
  39. 2026-09-01 08:09 UTCEG score recompute
  40. 2026-09-01 08:09 UTCGHSA enrichment
  41. 2026-09-01 04:40 UTCEPSS rescore
  42. 2026-09-01 04:40 UTCEPSS rescore
  43. 2026-08-31 19:13 UTCGHSA enrichment
  44. 2026-08-31 11:28 UTCGHSA enrichment
  45. 2026-08-30 22:28 UTCEG score recompute
  46. 2026-08-30 22:28 UTCGHSA enrichment
  47. 2026-08-30 19:18 UTCEPSS rescore
  48. 2026-08-30 19:17 UTCEPSS rescore
  49. 2026-08-30 09:38 UTCEG score recompute
  50. 2026-08-30 09:38 UTCGHSA enrichment
  51. 2026-08-30 01:22 UTCEPSS rescore
  52. 2026-08-29 20:45 UTCGHSA enrichment
  53. 2026-08-29 07:55 UTCEG score recompute
  54. 2026-08-29 07:55 UTCGHSA enrichment
  55. 2026-08-28 21:42 UTCEPSS rescore
  56. 2026-08-28 19:03 UTCGHSA enrichment
  57. 2026-08-28 09:21 UTCGHSA enrichment
  58. 2026-08-27 20:27 UTCEG score recompute
  59. 2026-08-27 20:27 UTCGHSA enrichment
  60. 2026-08-27 17:24 UTCEG score recompute
  61. 2026-08-27 16:47 UTCEG score recompute
  62. 2026-08-27 16:43 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-81726?
CVE-2026-81726 is a high vulnerability published on August 27, 2026. NLTK through 3.10.3 contains a path traversal vulnerability in model-artifact APIs that bypass pathsec enforcement by using raw file operations on caller-controlled paths. Attackers can read or write files outside allowed sandbox roots through TransitionParser, AveragedPerceptron, PerceptronTagger,…
When was CVE-2026-81726 disclosed?
CVE-2026-81726 was first published in the National Vulnerability Database on August 27, 2026, with the most recent update on August 31, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81726 actively exploited?
CVE-2026-81726 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 82.0% of all scored CVEs.
What is the CVSS score of CVE-2026-81726?
CVE-2026-81726 has a CVSS v3 base score of 7.0 (NVD).
How do I remediate CVE-2026-81726?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81726, 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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