CVE-2026-12252

HIGHPre-NVD 7.87.8—
EchelonGraph scoreHIGH confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-04. a secondary CVSS source baseline 7.8; sources differ by 0.0.

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

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

In nltk/nltk versions 3.9.3 and earlier, five Stanford interface classes (StanfordPOSTagger, StanfordNERTagger, StanfordParser, StanfordDependencyParser, and StanfordNeuralDependencyParser) are vulnerable to untrusted JAR code execution. These classes accept user-controllable JAR paths and execute them via the java() function, which invokes subprocess.Popen() without integrity verification. This vulnerability is identical to CVE-2026-0848, which was fixed for StanfordSegmenter by adding SHA256 verification. However, the fix was not applied to these additional classes, leaving them susceptible to arbitrary code execution when loading untrusted JAR files.

CVSS v3
7.8
EG Score
7.8(high)
EPSS
5.4%
KEV
Not listed

Published

July 4, 2026

Last Modified

July 8, 2026

Advisory Details (1)

Auto-updated Jul 4, 2026
No patch confirmed yet.
generic

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Vendor Advisories for CVE-2026-12252(1)

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

Affected Packages

(1 across 1 ecosystem)
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 9× 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.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:24 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:30 UTCEPSS rescore
  5. 2026-07-19 02:28 UTCEPSS rescore
  6. 2026-07-16 21:46 UTCGHSA enrichment
  7. 2026-07-16 17:02 UTCEPSS rescore
  8. 2026-07-16 09:56 UTCGHSA enrichment
  9. 2026-07-15 22:05 UTCGHSA enrichment
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 10:13 UTCGHSA enrichment
  12. 2026-07-15 02:00 UTCEPSS rescore
  13. 2026-07-14 22:19 UTCGHSA enrichment
  14. 2026-07-14 10:29 UTCGHSA enrichment
  15. 2026-07-13 22:38 UTCGHSA enrichment
  16. 2026-07-13 22:30 UTCEPSS rescore
  17. 2026-07-13 10:48 UTCGHSA enrichment
  18. 2026-07-13 06:12 UTCEPSS rescore
  19. 2026-07-12 22:58 UTCGHSA enrichment
  20. 2026-07-12 11:07 UTCGHSA enrichment
  21. 2026-07-12 05:46 UTCEPSS rescore
  22. 2026-07-11 23:17 UTCGHSA enrichment
  23. 2026-07-11 11:27 UTCGHSA enrichment
  24. 2026-07-11 08:27 UTCEPSS rescore
  25. 2026-07-10 23:37 UTCGHSA enrichment
Show 23 more
  1. 2026-07-10 11:46 UTCGHSA enrichment
  2. 2026-07-09 23:53 UTCGHSA enrichment
  3. 2026-07-09 19:10 UTCEPSS rescore
  4. 2026-07-09 12:03 UTCGHSA enrichment
  5. 2026-07-09 00:13 UTCGHSA enrichment
  6. 2026-07-08 15:15 UTCEPSS rescore
  7. 2026-07-08 15:15 UTCEPSS rescore
  8. 2026-07-08 12:22 UTCGHSA enrichment
  9. 2026-07-08 00:28 UTCGHSA enrichment
  10. 2026-07-07 13:46 UTCEPSS rescore
  11. 2026-07-07 12:39 UTCGHSA enrichment
  12. 2026-07-07 00:47 UTCGHSA enrichment
  13. 2026-07-06 16:27 UTCEPSS rescore
  14. 2026-07-06 12:57 UTCGHSA enrichment
  15. 2026-07-06 02:23 UTCEPSS rescore
  16. 2026-07-06 01:04 UTCGHSA enrichment
  17. 2026-07-05 13:14 UTCGHSA enrichment
  18. 2026-07-05 02:30 UTCEPSS rescore
  19. 2026-07-05 02:30 UTCEPSS rescore
  20. 2026-07-05 01:22 UTCGHSA enrichment
  21. 2026-07-04 13:32 UTCGHSA enrichment
  22. 2026-07-04 01:42 UTCEG score recompute
  23. 2026-07-04 01:41 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-12252?
CVE-2026-12252 is a high vulnerability published on July 4, 2026. In nltk/nltk versions 3.9.3 and earlier, five Stanford interface classes (StanfordPOSTagger, StanfordNERTagger, StanfordParser, StanfordDependencyParser, and StanfordNeuralDependencyParser) are vulnerable to untrusted JAR code execution. These classes accept user-controllable JAR paths and execute…
When was CVE-2026-12252 disclosed?
CVE-2026-12252 was first published in the National Vulnerability Database on July 4, 2026, with the most recent update on July 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12252 actively exploited?
CVE-2026-12252 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 5.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-12252?
CVE-2026-12252 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-12252?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12252, 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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