CVE-2026-79657

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-25. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: Elevated riskExposed: 0

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

NLTK versions before 3.10.3 contain a remote code execution vulnerability in allowlisted pickle loaders that trust entire module namespaces instead of specific safe callables. Attackers can craft malicious pickle payloads invoking dangerous in-namespace functions like ReppTokenizer._execute and numpy.f2py.crackfortran.myeval through pickle REDUCE to execute arbitrary commands during model or tokenizer artifact loading.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
75(Attend)
EG Risk 75/100SSVC: 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
Severity98% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
67%
KEV
Not listed

Published

August 25, 2026

Last Modified

August 31, 2026

Advisory Details (2)

Auto-updated Sep 14, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Allowlisted pickle loaders still permit code execution in current source · Advisory · nltk/nltk · GitHub

https://github.com/nltk/nltk/security/advisories/GHSA-x99w-6fgc-pmfw
generic

NLTK before 3.10.3 Remote Code Execution via Unsafe Pickle Deserialization | Advisories | VulnCheck

https://www.vulncheck.com/advisories/nltk-before-3.10.3-remote-code-execution-via-unsafe-pickle-deserialization

Vendor Advisories for CVE-2026-79657(1)

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

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, 3.10.1-1, 3.9.1-2, 3.9.2-1, 3.9.3-13.10.3-1—
PyPI(1)
PackageVulnerable rangeFixed inDependents
nltk0.8 ... 3.9b1 (68 versions)3.10.3—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 102× 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 102 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-79657?
CVE-2026-79657 is a critical vulnerability published on August 25, 2026. NLTK versions before 3.10.3 contain a remote code execution vulnerability in allowlisted pickle loaders that trust entire module namespaces instead of specific safe callables. Attackers can craft malicious pickle payloads invoking dangerous in-namespace functions like ReppTokenizer._execute and…
When was CVE-2026-79657 disclosed?
CVE-2026-79657 was first published in the National Vulnerability Database on August 25, 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-2026-79657 actively exploited?
CVE-2026-79657 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 32.9% of all scored CVEs.
What is the CVSS score of CVE-2026-79657?
CVE-2026-79657 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-79657?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-79657, 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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