CVE-2026-70626

MEDIUMPre-NVD 6.26.2—
EchelonGraph scoreHIGH confidence

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, ghsa, secondary
Elevated
6.2EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.2Exploit: Elevated riskExposed: 0

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

NLTK versions before 3.9.4 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
6.2(high)
EG Risk
44(Track)
EG Risk 44/100SSVC: 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
Severity62% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
11%
KEV
Not listed

Published

August 22, 2026

Last Modified

August 31, 2026

Advisory Details (2)

Auto-updated Aug 22, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

NLTK before 3.9.4 Symlink Escape via CorpusReader | Advisories | VulnCheck

https://www.vulncheck.com/advisories/nltk-before-symlink-escape-via-corpusreader
github Patch Available🟡 PoC Available

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 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, 3.9.2-1, 3.9.3-13.10.0-1—
PyPI(1)
PackageVulnerable rangeFixed inDependents
nltk0.8 ... 3.9b1 (64 versions)3.9.4—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 59× 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.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 14:26 UTCEG score recompute
  3. 2026-09-17 13:17 UTCEG score recompute
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 12:15 UTCEG score recompute
  6. 2026-09-16 05:15 UTCEPSS rescore
  7. 2026-09-15 11:14 UTCEG score recompute
  8. 2026-09-15 03:12 UTCEPSS rescore
  9. 2026-09-14 10:06 UTCEG score recompute
  10. 2026-09-13 08:50 UTCEG score recompute
  11. 2026-09-12 15:02 UTCEPSS rescore
  12. 2026-09-12 07:49 UTCEG score recompute
  13. 2026-09-11 14:53 UTCEPSS rescore
  14. 2026-09-11 06:48 UTCEG score recompute
  15. 2026-09-10 09:35 UTCEPSS rescore
  16. 2026-09-09 04:46 UTCEG score recompute
  17. 2026-09-08 22:01 UTCEPSS rescore
  18. 2026-09-08 03:31 UTCEG score recompute
  19. 2026-09-07 16:01 UTCEPSS rescore
  20. 2026-09-07 02:28 UTCEG score recompute
  21. 2026-09-06 13:47 UTCEPSS rescore
  22. 2026-09-06 00:50 UTCEG score recompute
  23. 2026-09-05 15:31 UTCEPSS rescore
  24. 2026-09-04 23:47 UTCEG score recompute
  25. 2026-09-04 05:07 UTCEPSS rescore
Show 34 more
  1. 2026-09-02 21:18 UTCEG score recompute
  2. 2026-09-02 14:12 UTCEPSS rescore
  3. 2026-09-01 20:17 UTCEG score recompute
  4. 2026-09-01 20:16 UTCGHSA enrichment
  5. 2026-09-01 13:54 UTCEPSS rescore
  6. 2026-09-01 04:40 UTCEPSS rescore
  7. 2026-08-31 19:14 UTCGHSA enrichment
  8. 2026-08-30 21:16 UTCEG score recompute
  9. 2026-08-30 21:16 UTCGHSA enrichment
  10. 2026-08-30 19:17 UTCEPSS rescore
  11. 2026-08-30 01:22 UTCEPSS rescore
  12. 2026-08-29 20:14 UTCEG score recompute
  13. 2026-08-29 20:14 UTCGHSA enrichment
  14. 2026-08-28 21:42 UTCEPSS rescore
  15. 2026-08-28 19:09 UTCGHSA enrichment
  16. 2026-08-27 23:43 UTCEG score recompute
  17. 2026-08-27 23:43 UTCGHSA enrichment
  18. 2026-08-26 22:42 UTCEG score recompute
  19. 2026-08-26 22:42 UTCGHSA enrichment
  20. 2026-08-26 14:47 UTCEPSS rescore
  21. 2026-08-25 21:41 UTCEG score recompute
  22. 2026-08-25 21:41 UTCGHSA enrichment
  23. 2026-08-25 13:49 UTCEPSS rescore
  24. 2026-08-24 20:26 UTCEG score recompute
  25. 2026-08-24 20:26 UTCGHSA enrichment
  26. 2026-08-24 20:02 UTCEG score recompute
  27. 2026-08-24 20:02 UTCGHSA enrichment
  28. 2026-08-24 17:26 UTCEG score recompute
  29. 2026-08-24 17:26 UTCGHSA enrichment
  30. 2026-08-23 16:25 UTCEG score recompute
  31. 2026-08-23 16:25 UTCGHSA enrichment
  32. 2026-08-22 15:24 UTCEG score recompute
  33. 2026-08-22 14:26 UTCEG score recompute
  34. 2026-08-22 14:25 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-70626?
CVE-2026-70626 is a medium vulnerability 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 disclosed?
CVE-2026-70626 was first published in the National Vulnerability Database on August 22, 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-2026-70626 actively exploited?
CVE-2026-70626 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 89.2% of all scored CVEs.
What is the CVSS score of CVE-2026-70626?
CVE-2026-70626 has a CVSS v3 base score of 6.2 (NVD).
How do I remediate CVE-2026-70626?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-70626, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-70626

Explore →

Is Your Infrastructure Affected by CVE-2026-70626?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs