CVE-2026-79657

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

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, GitHub Security Advisory, a secondary CVSS source
Elevated
9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 1.3%CVSS: 9.8Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

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
9.8CRITICALmedium confidence
EG Risk
75
EG Risk 75/100

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 (value × EchelonGraph’s weight)
Severity98% × 45%
The EG Score, 9.8 of 10.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
1.3%
EPSS %ILE
69th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 25, 2026

Last Modified

October 8, 2026

Advisory Details (2)

Auto-updated Oct 8, 2026
Patch available. Sources: github.
GitHub advisoryMentions a patch (unverified)

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
Web page

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 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
nltk3.10.0-1, 3.10.1-1, 3.9.1-2, 3.9.2-1, 3.9.3-1
  • every version up to 3.10.3-1: fixed in 3.10.3-1
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
nltk0.8 ... 3.9b1 (68 versions)
  • every version up to 3.10.3: fixed in 3.10.3
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 18× in last 7d / 62× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 97 of 152 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 3 repeat rows among the latest 100 are merged into the row they repeat. The 55 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 01:38 UTCEG score recompute
  2. 2026-10-13 16:35 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  3. 2026-10-12 21:48 UTCEG score recompute
  4. 2026-10-12 16:35 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  5. 2026-10-12 14:58 UTCEG score recompute
  6. 2026-10-11 19:22 UTCEG score recompute
  7. 2026-10-11 16:38 UTCEG score recompute
  8. 2026-10-11 13:56 UTCEG score recompute
  9. 2026-10-11 13:49 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  10. 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  11. 2026-10-10 12:17 UTCEG score recompute
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  13. 2026-10-09 04:30 UTCEG score recompute
  14. 2026-10-08 17:13 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  15. 2026-10-08 16:36 UTCEG score recompute
  16. 2026-10-08 15:41 UTCEG score recompute
  17. 2026-10-08 03:32 UTCEG score recompute
  18. 2026-10-07 23:48 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  19. 2026-10-06 16:09 UTCEG score recompute
  20. 2026-10-06 15:18 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  21. 2026-10-05 20:50 UTCEG score recompute
  22. 2026-10-05 17:43 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  23. 2026-10-04 23:38 UTCEG score recompute
  24. 2026-10-04 23:22 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  25. 2026-10-03 16:27 UTCEG score recompute
Show 72 more
  1. 2026-10-03 14:26 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  2. 2026-10-02 21:39 UTCEG score recompute
  3. 2026-10-02 17:57 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  4. 2026-10-01 20:15 UTCEG score recompute
  5. 2026-10-01 19:50 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  6. 2026-09-30 20:16 UTCEG score recompute
  7. 2026-09-30 06:51 UTCEG score recompute
  8. 2026-09-29 15:24 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  9. 2026-09-29 01:36 UTCEG score recompute
  10. 2026-09-28 21:30 UTCEG score recompute
  11. 2026-09-28 13:52 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  12. 2026-09-27 14:31 UTCEG score recompute
  13. 2026-09-27 13:48 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  14. 2026-09-26 22:07 UTCEG score recompute
  15. 2026-09-26 15:59 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  16. 2026-09-26 00:28 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  17. 2026-09-24 16:51 UTCEG score recompute
  18. 2026-09-24 14:04 UTCEPSS rescoreEPSS 1.3% · 68th percentile
  19. 2026-09-24 12:51 UTCEG score recompute
  20. 2026-09-23 17:55 UTCEG score recompute
  21. 2026-09-23 17:54 UTCEPSS rescoreEPSS 1.2% · 67th percentile
  22. 2026-09-22 19:06 UTCEG score recompute
  23. 2026-09-22 16:01 UTCEPSS rescoreEPSS 1.2% · 67th percentile
  24. 2026-09-21 22:50 UTCEG score recompute
  25. 2026-09-21 21:09 UTCEPSS rescoreEPSS 1.2% · 66th percentile
  26. 2026-09-21 00:01 UTCEG score recompute
  27. 2026-09-20 20:16 UTCEPSS rescoreEPSS 1.2% · 67th percentile
  28. 2026-09-19 16:36 UTCEG score recompute
  29. 2026-09-18 21:34 UTCEG score recompute
  30. 2026-09-18 19:28 UTCEPSS rescoreEPSS 1.2% · 67th percentile
  31. 2026-09-17 21:09 UTCEG score recompute
  32. 2026-09-16 14:56 UTCEG score recompute
  33. 2026-09-16 14:08 UTCEPSS rescoreEPSS 1.2% · 66th percentile
  34. 2026-09-16 07:14 UTCEG score recompute
  35. 2026-09-16 05:15 UTCEPSS rescoreEPSS 1.2% · 66th percentile
  36. 2026-09-15 03:52 UTCEG score recompute
  37. 2026-09-15 03:12 UTCEPSS rescoreEPSS 1.2% · 66th percentile
  38. 2026-09-13 17:32 UTCEG score recompute
  39. 2026-09-12 18:49 UTCEG score recompute
  40. 2026-09-11 15:48 UTCEG score recompute
  41. 2026-09-11 14:53 UTCEPSS rescoreEPSS 1.2% · 66th percentile
  42. 2026-09-11 12:01 UTCEG score recompute
  43. 2026-09-10 12:04 UTCEG score recompute
  44. 2026-09-09 01:16 UTCEG score recompute
  45. 2026-09-08 22:01 UTCEPSS rescoreEPSS 1.2% · 66th percentile
  46. 2026-09-07 19:05 UTCEG score recompute
  47. 2026-09-06 17:24 UTCEG score recompute
  48. 2026-09-06 13:48 UTCEPSS rescoreEPSS 1.2% · 66th percentile
  49. 2026-09-05 18:41 UTCEG score recompute
  50. 2026-09-04 15:12 UTCEG score recompute
  51. 2026-09-04 07:37 UTCEG score recompute
  52. 2026-09-04 05:07 UTCEPSS rescoreEPSS 1.2% · 66th percentile
  53. 2026-09-02 17:03 UTCEG score recompute
  54. 2026-09-02 14:12 UTCEPSS rescoreEPSS 1.2% · 66th percentile
  55. 2026-09-02 13:11 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  56. 2026-09-02 09:19 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  57. 2026-09-02 05:32 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  58. 2026-09-02 01:43 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  59. 2026-09-01 21:53 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  60. 2026-09-01 18:06 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  61. 2026-09-01 14:14 UTCEG score recompute
  62. 2026-09-01 14:14 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  63. 2026-09-01 13:54 UTCEPSS rescoreEPSS 1.2% · 66th percentile
  64. 2026-09-01 10:24 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-09-01 06:37 UTCEG score recompute
  66. 2026-09-01 06:37 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  67. 2026-09-01 04:40 UTCEPSS rescoreEPSS 1.2% · 65th percentile
  68. 2026-09-01 02:49 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  69. 2026-08-31 23:02 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  70. 2026-08-31 19:14 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  71. 2026-08-31 17:40 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8
  72. 2026-08-31 13:13 UTCGHSA enrichmentGHSA-vp9c-2pjm-8925 · GitHub severity CRITICAL · GitHub CVSS 9.8

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Frequently asked(5)

What is CVE-2026-79657?
CVE-2026-79657 is a critical-severity vulnerability; its CVE record was 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 made public?
CVE-2026-79657 was made public on August 11, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on August 25, 2026. EchelonGraph's copy of the record carries a last-modified date of October 8, 2026; the record at its source may have been updated since.
Is CVE-2026-79657 actively exploited?
CVE-2026-79657 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.3% probability of exploitation in the next 30 days (69th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-79657?
CVE-2026-79657 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-79657?
A fix for CVE-2026-79657 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-79657 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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