CVE-2026-70626

MEDIUMPre-NVD 6.26.2
EchelonGraph scoreMEDIUM confidence

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

Score 6.2 from GitHub Security Advisory (severity: HIGH) published 2026-08-22. A secondary CVSS source baseline 6.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Elevated
6.2EG
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: 0.2%CVSS: 6.2Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not account for symlink resolution, enabling attackers to place symlinks inside the corpus root to access files outside the intended boundary.

CVSS v3
6.2
EG Score
6.2MEDIUMmedium confidence
EG Risk
44
EG Risk 44/100

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)
Severity62% × 45%
The EG Score, 6.2 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
0.2%
EPSS %ILE
9th
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

October 14, 2026

Advisory Details (2)

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

NLTK before 3.9.4 Symlink Escape via CorpusReader | Advisories | VulnCheck

https://www.vulncheck.com/advisories/nltk-before-symlink-escape-via-corpusreader
GitHub advisoryMentions a patch (unverified)

Symlink escape in CorpusReader allows arbitrary local file read outside the corpus root · Advisory · nltk/nltk · GitHub

https://github.com/nltk/nltk/security/advisories/GHSA-r6gq-whwq-mvg9

Vendor Advisories for CVE-2026-70626(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 (64 versions)
  • every version up to 3.9.4: fixed in 3.9.4
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 50× 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 100 of 101 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. None are among the latest 100 rows. The 1 oldest row on record is not shown and was not checked, so the counts can still include repeats.

  1. 2026-10-14 13:36 UTCEG score recompute
  2. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  3. 2026-10-12 15:43 UTCEG score recompute
  4. 2026-10-11 19:29 UTCEG score recompute
  5. 2026-10-11 16:44 UTCEG score recompute
  6. 2026-10-11 14:04 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  9. 2026-10-10 16:35 UTCEG score recompute
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  11. 2026-10-09 06:06 UTCEG score recompute
  12. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  13. 2026-10-08 05:04 UTCEG score recompute
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  15. 2026-10-07 04:03 UTCEG score recompute
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  17. 2026-10-06 03:01 UTCEG score recompute
  18. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  19. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  20. 2026-10-03 16:38 UTCEG score recompute
  21. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  22. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  23. 2026-10-02 09:37 UTCEG score recompute
  24. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  25. 2026-10-01 08:36 UTCEG score recompute
Show 75 more
  1. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  2. 2026-09-30 07:32 UTCEG score recompute
  3. 2026-09-29 03:19 UTCEG score recompute
  4. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  5. 2026-09-28 02:10 UTCEG score recompute
  6. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  7. 2026-09-27 01:06 UTCEG score recompute
  8. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  9. 2026-09-24 22:22 UTCEG score recompute
  10. 2026-09-23 20:43 UTCEG score recompute
  11. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  12. 2026-09-22 19:42 UTCEG score recompute
  13. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  14. 2026-09-21 17:47 UTCEG score recompute
  15. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  16. 2026-09-20 16:41 UTCEG score recompute
  17. 2026-09-19 15:38 UTCEG score recompute
  18. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  19. 2026-09-18 14:26 UTCEG score recompute
  20. 2026-09-17 13:17 UTCEG score recompute
  21. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  22. 2026-09-16 12:15 UTCEG score recompute
  23. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  24. 2026-09-15 11:14 UTCEG score recompute
  25. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  26. 2026-09-14 10:06 UTCEG score recompute
  27. 2026-09-13 08:50 UTCEG score recompute
  28. 2026-09-12 15:02 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  29. 2026-09-12 07:49 UTCEG score recompute
  30. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  31. 2026-09-11 06:48 UTCEG score recompute
  32. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  33. 2026-09-09 04:46 UTCEG score recompute
  34. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  35. 2026-09-08 03:31 UTCEG score recompute
  36. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  37. 2026-09-07 02:28 UTCEG score recompute
  38. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  39. 2026-09-06 00:50 UTCEG score recompute
  40. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  41. 2026-09-04 23:47 UTCEG score recompute
  42. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  43. 2026-09-02 21:18 UTCEG score recompute
  44. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  45. 2026-09-01 20:17 UTCEG score recompute
  46. 2026-09-01 20:16 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  47. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  48. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  49. 2026-08-31 19:14 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  50. 2026-08-30 21:16 UTCEG score recompute
  51. 2026-08-30 21:16 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  52. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  53. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  54. 2026-08-29 20:14 UTCEG score recompute
  55. 2026-08-29 20:14 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  56. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  57. 2026-08-28 19:09 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  58. 2026-08-27 23:43 UTCEG score recompute
  59. 2026-08-27 23:43 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  60. 2026-08-26 22:42 UTCEG score recompute
  61. 2026-08-26 22:42 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  62. 2026-08-26 14:47 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  63. 2026-08-25 21:41 UTCEG score recompute
  64. 2026-08-25 21:41 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  65. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  66. 2026-08-24 20:26 UTCEG score recompute
  67. 2026-08-24 20:26 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  68. 2026-08-24 20:02 UTCEG score recompute
  69. 2026-08-24 20:02 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  70. 2026-08-24 17:26 UTCEG score recompute
  71. 2026-08-24 17:26 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  72. 2026-08-23 16:25 UTCEG score recompute
  73. 2026-08-23 16:25 UTCGHSA enrichmentGHSA-8h9m-22mv-qv5r · GitHub severity HIGH · GitHub CVSS 6.2
  74. 2026-08-22 15:24 UTCEG score recompute
  75. 2026-08-22 14:26 UTCEG score recomputeFirst assessed: 6.2 MEDIUM

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-70626?
CVE-2026-70626 is a medium-severity vulnerability; its CVE record was published on August 22, 2026. NLTK versions before 3.9.4 contain a symlink escape vulnerability in CorpusReader.open() that allows local attackers to read arbitrary files outside the corpus root. The vulnerability exists because path validation is lexical and does not account for symlink resolution, enabling attackers to place…
When was CVE-2026-70626 made public?
CVE-2026-70626 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 October 14, 2026; the record at its source may have been updated since.
Is CVE-2026-70626 actively exploited?
CVE-2026-70626 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (9th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-70626?
CVE-2026-70626 has a CVSS base score of 6.2 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-70626?
A fix for CVE-2026-70626 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-70626 are linked in the Vendor Advisories panel on this page.

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