CVE-2026-12372

LOWPre-NVD 3.73.7—
EchelonGraph scoreMEDIUM confidence

Score 3.7 from GitHub Security Advisory (severity: LOW) published 2026-08-10. a secondary CVSS source baseline 3.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
3.7EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 3.7Exploit: Elevated riskExposed: 0

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

A Server-Side Request Forgery (SSRF) vulnerability exists in nltk/nltk versions 3.9.4 and the current develop branch. The nltk.pathsec.validate_network_url() function, intended to prevent SSRF by rejecting internal network addresses, fails to reject IPs in the RFC 6598 shared address space (100.64.0.0/10). This occurs because Python's ipaddress module does not classify such addresses as is_private or is_global, and the current guard only checks is_private and a few explicit categories. An attacker who can influence a URL passed to NLTK's network-loading helpers can exploit this vulnerability to make a strict-mode application send requests to shared-address-space hosts, potentially exposing non-public infrastructure reachable from the application host. The impact is limited to SSRF-style confidentiality exposure, with no code execution claimed.

CVSS v3
3.7
EG Score
3.7(medium)
EG Risk
33(Track)
EG Risk 33/100SSVC: 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
Severity37% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
18%
KEV
Not listed

Published

August 9, 2026

Last Modified

September 4, 2026

References (2)

Vendor Advisories for CVE-2026-12372(1)

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

Affected Packages

(3 across 3 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
nltk3.10.0-1 ... 3.9.3-1 (6 versions)——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 41× 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. 2026-09-20 20:15 UTCEPSS rescore
  2. 2026-09-20 01:36 UTCEG score recompute
  3. 2026-09-20 01:36 UTCGHSA enrichment
  4. 2026-09-18 19:27 UTCEPSS rescore
  5. 2026-09-17 00:51 UTCEG score recompute
  6. 2026-09-17 00:51 UTCGHSA enrichment
  7. 2026-09-16 05:14 UTCEPSS rescore
  8. 2026-09-13 19:13 UTCEG score recompute
  9. 2026-09-13 19:13 UTCGHSA enrichment
  10. 2026-09-13 16:46 UTCEPSS rescore
  11. 2026-09-12 15:00 UTCEPSS rescore
  12. 2026-09-11 14:52 UTCEPSS rescore
  13. 2026-09-11 09:36 UTCEPSS rescore
  14. 2026-09-10 18:20 UTCEG score recompute
  15. 2026-09-10 18:20 UTCGHSA enrichment
  16. 2026-09-10 09:34 UTCEPSS rescore
  17. 2026-09-08 22:00 UTCEPSS rescore
  18. 2026-09-07 17:34 UTCEG score recompute
  19. 2026-09-07 17:34 UTCGHSA enrichment
  20. 2026-09-07 16:01 UTCEPSS rescore
  21. 2026-09-06 13:47 UTCEPSS rescore
  22. 2026-09-04 14:07 UTCEG score recompute
  23. 2026-09-04 14:07 UTCGHSA enrichment
  24. 2026-09-04 05:06 UTCEPSS rescore
  25. 2026-09-03 20:32 UTCEG score recompute
Show 40 more
  1. 2026-09-03 20:32 UTCGHSA enrichment
  2. 2026-09-02 14:11 UTCEPSS rescore
  3. 2026-09-01 13:53 UTCEPSS rescore
  4. 2026-09-01 04:39 UTCEPSS rescore
  5. 2026-08-31 19:41 UTCGHSA enrichment
  6. 2026-08-30 23:08 UTCEG score recompute
  7. 2026-08-30 23:08 UTCGHSA enrichment
  8. 2026-08-30 19:17 UTCEPSS rescore
  9. 2026-08-30 01:21 UTCEPSS rescore
  10. 2026-08-28 21:40 UTCEPSS rescore
  11. 2026-08-27 22:23 UTCEG score recompute
  12. 2026-08-27 22:23 UTCGHSA enrichment
  13. 2026-08-25 13:48 UTCEPSS rescore
  14. 2026-08-24 21:38 UTCEG score recompute
  15. 2026-08-24 21:38 UTCGHSA enrichment
  16. 2026-08-23 00:19 UTCEPSS rescore
  17. 2026-08-21 23:48 UTCEPSS rescore
  18. 2026-08-21 20:34 UTCEG score recompute
  19. 2026-08-21 20:34 UTCGHSA enrichment
  20. 2026-08-20 22:55 UTCEPSS rescore
  21. 2026-08-19 17:03 UTCEPSS rescore
  22. 2026-08-18 19:48 UTCEG score recompute
  23. 2026-08-18 19:48 UTCGHSA enrichment
  24. 2026-08-18 13:48 UTCEPSS rescore
  25. 2026-08-16 14:56 UTCEPSS rescore
  26. 2026-08-16 02:14 UTCEPSS rescore
  27. 2026-08-15 19:04 UTCEG score recompute
  28. 2026-08-15 19:04 UTCGHSA enrichment
  29. 2026-08-15 01:30 UTCEPSS rescore
  30. 2026-08-13 22:00 UTCEPSS rescore
  31. 2026-08-12 18:19 UTCEG score recompute
  32. 2026-08-12 18:19 UTCGHSA enrichment
  33. 2026-08-12 17:51 UTCEG score recompute
  34. 2026-08-12 17:51 UTCGHSA enrichment
  35. 2026-08-12 13:50 UTCEPSS rescore
  36. 2026-08-11 13:42 UTCEPSS rescore
  37. 2026-08-10 23:59 UTCEPSS rescore
  38. 2026-08-09 23:19 UTCEG score recompute
  39. 2026-08-09 22:56 UTCEG score recompute
  40. 2026-08-09 22:56 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-12372?
CVE-2026-12372 is a low vulnerability published on August 9, 2026. A Server-Side Request Forgery (SSRF) vulnerability exists in nltk/nltk versions 3.9.4 and the current develop branch. The nltk.pathsec.validatenetworkurl() function, intended to prevent SSRF by rejecting internal network addresses, fails to reject IPs in the RFC 6598 shared address space…
When was CVE-2026-12372 disclosed?
CVE-2026-12372 was first published in the National Vulnerability Database on August 9, 2026, with the most recent update on September 4, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12372 actively exploited?
CVE-2026-12372 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 82.0% of all scored CVEs.
What is the CVSS score of CVE-2026-12372?
CVE-2026-12372 has a CVSS v3 base score of 3.7 (NVD).
How do I remediate CVE-2026-12372?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12372, 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-2026-12372

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