CVE-2025-71408

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-25. a secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: Elevated riskExposed: 0

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

NLTK (Natural Language Toolkit) before version 3.9.3 contains an eval injection vulnerability in the nltk.collocations module that allows an attacker who controls command-line arguments to execute arbitrary Python code. When collocations.py is invoked directly, the __main__ block passes command-line arguments directly to eval() as suffixes of BigramAssocMeasures without allowlist validation or sanitization, enabling an attacker to supply a Python expression that escapes the intended attribute lookup and executes arbitrary code including OS commands via the os module.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
51(Track*)
EG Risk 51/100SSVC: 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
Severity78% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
0%
EPSS %ILE
10%
KEV
Not listed

Published

July 24, 2026

Last Modified

August 10, 2026

Advisory Details (4)

Auto-updated Jul 24, 2026
🔬 Proof of concept available. Patch available. Sources: github_pr, github_commit.
generic

NLTK < 3.9.2 Eval Injection via collocations.py Command-Line Arguments | Advisories | VulnCheck

https://www.vulncheck.com/advisories/nltk-eval-injection-via-collocations-py-command-line-arguments
github_commit Patch Available

commit 66f14096d952 (nltk/nltk)

Patch available: nltk/nltk v3.10.0-rc1 (contains commit 66f14096d952)

https://github.com/nltk/nltk/commit/66f14096d952ec8f04934f515e027534bd4eb0ac
github_pr Patch Available

replace eval() with getattr() in collocations CLI

Patch available: nltk/nltk v3.10.0-rc1 (PR #3465 merged 2025-12-03)

https://github.com/nltk/nltk/pull/3465
generic🟡 PoC Available

NLTK Command Injection via eval() in collocations.py

https://aydinnyunus.github.io/2026/06/07/command-injection-nltk-collocations-eval/

Vendor Advisories for CVE-2025-71408(1)

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

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 (9 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
nltk3.10.0-1 ... 3.9.3-1 (6 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
nltk3.9.1-2, 3.9.2-13.9.3-1—
PyPI(1)
PackageVulnerable rangeFixed inDependents
nltk0.8 ... 3.9b1 (63 versions)3.9.3—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 48× 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 134 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2025-71408?
CVE-2025-71408 is a high vulnerability published on July 24, 2026. NLTK (Natural Language Toolkit) before version 3.9.3 contains an eval injection vulnerability in the nltk.collocations module that allows an attacker who controls command-line arguments to execute arbitrary Python code. When collocations.py is invoked directly, the main block passes command-line…
When was CVE-2025-71408 disclosed?
CVE-2025-71408 was first published in the National Vulnerability Database on July 24, 2026, with the most recent update on August 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-71408 actively exploited?
CVE-2025-71408 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 90.2% of all scored CVEs.
What is the CVSS score of CVE-2025-71408?
CVE-2025-71408 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2025-71408?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-71408, 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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