CVE-2026-65915

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

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

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-22. A secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Elevated
6.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (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: 0.4%CVSS: 6.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

NLTK versions before 3.10.0 contain a logic bug in FileSystemPathPointer.open() where the sandbox validation check compares a normalized path against itself, making the security check permanently inert. Attackers can pass file:// URLs to nltk.data.load() to read arbitrary files accessible to the process user, including credentials and configuration files.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
45
EG Risk 45/100

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)
Severity65% × 45%
The EG Score, 6.5 of 10.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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.
EPSS PROB
0.4%
EPSS %ILE
33rd
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (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 22, 2026

Last Modified

August 31, 2026

Advisory Details (2)

Auto-updated Aug 22, 2026
Patch available. Sources: github.
Web page

NLTK before 3.10.0 Arbitrary File Read via FileSystemPathPointer | Advisories | VulnCheck

https://www.vulncheck.com/advisories/nltk-before-arbitrary-file-read-via-filesystempathpointer
GitHub advisoryMentions a patch (unverified)

FileSystemPathPointer.open() sandbox check is dead code — arbitrary file read via file:// protocol · Advisory · nltk/nltk · GitHub

https://github.com/nltk/nltk/security/advisories/GHSA-72r2-7mfr-5xr9

Vendor Advisories for CVE-2026-65915(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
nltk3.9.1-2, 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 (65 versions)
  • every version up to 3.10.0: fixed in 3.10.0
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 48× 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.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  3. 2026-10-12 15:46 UTCEG score recompute
  4. 2026-10-11 19:31 UTCEG score recompute
  5. 2026-10-11 16:46 UTCEG score recompute
  6. 2026-10-11 14:07 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  9. 2026-10-10 16:35 UTCEG score recompute
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  11. 2026-10-09 05:33 UTCEG score recompute
  12. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  13. 2026-10-08 05:41 UTCEG score recompute
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  15. 2026-10-07 06:44 UTCEG score recompute
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  17. 2026-10-06 07:48 UTCEG score recompute
  18. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  19. 2026-10-05 04:53 UTCEG score recompute
  20. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  21. 2026-10-04 05:25 UTCEG score recompute
  22. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  23. 2026-10-03 06:29 UTCEG score recompute
  24. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  25. 2026-10-02 06:45 UTCEG score recompute
Show 75 more
  1. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  2. 2026-10-01 06:29 UTCEG score recompute
  3. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  4. 2026-09-30 07:33 UTCEG score recompute
  5. 2026-09-28 23:23 UTCEG score recompute
  6. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  7. 2026-09-28 00:08 UTCEG score recompute
  8. 2026-09-27 01:08 UTCEG score recompute
  9. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  10. 2026-09-24 18:58 UTCEG score recompute
  11. 2026-09-23 20:00 UTCEG score recompute
  12. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  13. 2026-09-22 19:42 UTCEG score recompute
  14. 2026-09-21 18:25 UTCEG score recompute
  15. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  16. 2026-09-19 20:33 UTCEG score recompute
  17. 2026-09-18 21:37 UTCEG score recompute
  18. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  19. 2026-09-17 21:15 UTCEG score recompute
  20. 2026-09-16 19:40 UTCEG score recompute
  21. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  22. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  23. 2026-09-15 19:14 UTCEG score recompute
  24. 2026-09-13 21:19 UTCEG score recompute
  25. 2026-09-12 22:22 UTCEG score recompute
  26. 2026-09-11 23:26 UTCEG score recompute
  27. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  28. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  29. 2026-09-11 00:16 UTCEG score recompute
  30. 2026-09-09 01:42 UTCEG score recompute
  31. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  32. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  33. 2026-09-07 12:09 UTCEG score recompute
  34. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  35. 2026-09-06 13:00 UTCEG score recompute
  36. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  37. 2026-09-04 15:03 UTCEG score recompute
  38. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  39. 2026-09-02 16:46 UTCEG score recompute
  40. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  41. 2026-09-01 17:42 UTCEG score recompute
  42. 2026-09-01 17:42 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  43. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  44. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  45. 2026-08-31 18:44 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  46. 2026-08-31 17:56 UTCEG score recompute
  47. 2026-08-31 17:55 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  48. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  49. 2026-08-30 17:04 UTCEG score recompute
  50. 2026-08-30 17:04 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  51. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  52. 2026-08-29 18:08 UTCEG score recompute
  53. 2026-08-29 18:07 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  54. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  55. 2026-08-28 19:09 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  56. 2026-08-28 18:03 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  57. 2026-08-27 18:18 UTCEG score recompute
  58. 2026-08-27 18:18 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  59. 2026-08-26 18:21 UTCEG score recompute
  60. 2026-08-26 18:20 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  61. 2026-08-26 14:47 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  62. 2026-08-25 19:22 UTCEG score recompute
  63. 2026-08-25 19:22 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  64. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  65. 2026-08-24 20:26 UTCEG score recompute
  66. 2026-08-24 20:26 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  67. 2026-08-24 19:36 UTCEG score recompute
  68. 2026-08-24 19:36 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  69. 2026-08-24 13:16 UTCEG score recompute
  70. 2026-08-24 13:16 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  71. 2026-08-23 14:20 UTCEG score recompute
  72. 2026-08-23 14:20 UTCGHSA enrichmentGHSA-79ph-w9m5-4v5m · GitHub severity HIGH · GitHub CVSS 6.5
  73. 2026-08-22 15:24 UTCEG score recompute
  74. 2026-08-22 14:26 UTCEG score recomputeFirst assessed: 6.5 MEDIUM
  75. 2026-08-22 14:25 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-65915?
CVE-2026-65915 is a medium-severity vulnerability; its CVE record was published on August 22, 2026. NLTK versions before 3.10.0 contain a logic bug in FileSystemPathPointer.open() where the sandbox validation check compares a normalized path against itself, making the security check permanently inert. Attackers can pass file:// URLs to nltk.data.load() to read arbitrary files accessible to the…
When was CVE-2026-65915 made public?
CVE-2026-65915 was made public on August 7, 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 22, 2026. EchelonGraph's copy of the record carries a last-modified date of August 31, 2026; the record at its source may have been updated since.
Is CVE-2026-65915 actively exploited?
CVE-2026-65915 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (33rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-65915?
CVE-2026-65915 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-65915?
A fix for CVE-2026-65915 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-65915 are linked in the Vendor Advisories panel on this page.

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