CVE-2026-102598

MEDIUMPre-NVD 6.36.3
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (31st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source

Also known asEUVD-2026-88980 (ENISA EUVD) · GHSA-g6x2-hccm-hh4m (GitHub Security Advisories) · PYSEC-2026-4312 (OSV.dev)Source: ENISA EUVD

6.3EG
EchelonGraph verdictMonitorRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 6.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Werkzeug is a comprehensive WSGI web application library. Prior to 3.1.9, the safe_join function used by send_from_directory can allow a NUL: special-device path because safe_join checks the Windows device name without first removing an empty NTFS ADS marker. The trigger is that an application runs on Windows with NTFS and serves a user-specified path ending in a special device name such as NUL:. The attack mechanism is that a requested path ends in a Windows special device name with an empty ADS marker. The impact is that the special device opens successfully and the file read hangs indefinitely. This issue is fixed in version 3.1.9.

CVSS
6.3
EG Score
6.3MEDIUMmedium confidence
EG Risk
43
EG Risk 43/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity63% × 45%
Impact severity (EG Severity): CVSS 6.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.4%
EPSS %ILE
31st
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (6.3): severity, escalated by confirmed exploitation. This CVE's 6.3 is its impact severity (EG Severity), not escalated.

EG Severity
6.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-10). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

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

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (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)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

September 29, 2026

Last Modified

September 30, 2026

Advisory Details (4)

Auto-updated Sep 29, 2026
Patch available. Sources: github, github_pr, github_commit, github_release.
GitHub release Patch Available

Release 3.1.9 (pallets/werkzeug)

Patch available: pallets/werkzeug 3.1.9

https://github.com/pallets/werkzeug/releases/tag/3.1.9
GitHub commit Patch Available

commit 8d77320bcdf3 (pallets/werkzeug)

Patch available: pallets/werkzeug 3.1.9 (contains commit 8d77320bcdf3)

https://github.com/pallets/werkzeug/commit/8d77320bcdf3a34941ec06dcf16b03c065cd21b6
GitHub pull request Patch Available

disallow special name with ads

Patch available: pallets/werkzeug 3.1.9 (PR #3309 merged 2026-09-27)

https://github.com/pallets/werkzeug/pull/3309
GitHub advisoryMentions a patch (unverified)

Werkzeug safe_join() allows Windows special device names · Advisory · pallets/werkzeug · GitHub

https://github.com/pallets/werkzeug/security/advisories/GHSA-g6x2-hccm-hh4m

Patch Availability(6)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrhaii/vllm-cpu-rhel9:17918573012026-10-14redhat
redhatrhaii/vllm-cuda-rhel9:17918571832026-10-14redhat
redhatrhaii/vllm-cuda-rhel9:17914736312026-10-13redhat
redhatrhaii/vllm-cpu-rhel9:17914736142026-10-13redhat
redhatrhaii/vllm-gaudi-rhel9:17914271822026-10-13redhat
pipWerkzeug @ 3.1.9 (fixes < 3.1.9)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
werkzeug0.1 ... 3.1.8 (106 versions)
  • every version up to 3.1.9: fixed in 3.1.9
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 36× 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 its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS → 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

  1. 2026-11-13 16:50 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  2. 2026-11-12 16:32 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  3. 2026-11-11 16:37 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  4. 2026-11-11 05:51 UTCEchelonGraph re-scored
  5. 2026-11-11 05:51 UTCGHSA enrichmentGHSA-g6x2-hccm-hh4m · GitHub severity MODERATE
  6. 2026-11-10 16:41 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  7. 2026-11-09 16:33 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  8. 2026-11-08 16:37 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  9. 2026-11-07 16:37 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  10. 2026-11-06 16:35 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  11. 2026-11-05 16:36 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  12. 2026-11-04 16:34 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  13. 2026-11-04 00:31 UTCEchelonGraph re-scored
  14. 2026-11-04 00:31 UTCVendor advisory
  15. 2026-11-04 00:31 UTCGHSA enrichmentGHSA-g6x2-hccm-hh4m · GitHub severity MODERATE
  16. 2026-11-03 16:45 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  17. 2026-11-02 16:43 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  18. 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  19. 2026-11-01 08:00 UTCGHSA enrichmentGHSA-g6x2-hccm-hh4m · GitHub severity MODERATE
  20. 2026-11-01 08:00 UTCEchelonGraph re-scored
  21. 2026-10-31 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  22. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  23. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  24. 2026-10-29 14:49 UTCEchelonGraph re-scored
  25. 2026-10-29 14:49 UTCVendor advisory
Show 57 more
  1. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  2. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  3. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  4. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  5. 2026-10-25 14:56 UTCEchelonGraph re-scored
  6. 2026-10-24 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  7. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  8. 2026-10-23 09:28 UTCEchelonGraph re-scored
  9. 2026-10-23 09:28 UTCVendor advisory
  10. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  11. 2026-10-21 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  12. 2026-10-20 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  13. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  14. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  15. 2026-10-18 05:10 UTCEchelonGraph re-scored
  16. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  17. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  18. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  19. 2026-10-14 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  20. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  21. 2026-10-12 16:41 UTCEchelonGraph re-scored
  22. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  23. 2026-10-11 20:16 UTCEchelonGraph re-scored
  24. 2026-10-11 16:54 UTCEchelonGraph re-scored
  25. 2026-10-11 16:54 UTCVendor advisory
  26. 2026-10-11 15:02 UTCEchelonGraph re-scored
  27. 2026-10-11 13:47 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  28. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  29. 2026-10-10 14:51 UTCEchelonGraph re-scored
  30. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  31. 2026-10-09 12:48 UTCEchelonGraph re-scored
  32. 2026-10-09 12:48 UTCVendor advisory
  33. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  34. 2026-10-08 10:44 UTCEchelonGraph re-scored
  35. 2026-10-08 10:44 UTCVendor advisory
  36. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  37. 2026-10-07 08:27 UTCEchelonGraph re-scored
  38. 2026-10-07 08:27 UTCVendor advisory
  39. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  40. 2026-10-06 06:12 UTCEchelonGraph re-scored
  41. 2026-10-06 06:12 UTCVendor advisory
  42. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  43. 2026-10-05 04:07 UTCEchelonGraph re-scored
  44. 2026-10-05 04:07 UTCVendor advisory
  45. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  46. 2026-10-04 02:01 UTCEchelonGraph re-scored
  47. 2026-10-04 02:01 UTCVendor advisory
  48. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  49. 2026-10-02 23:57 UTCEchelonGraph re-scored
  50. 2026-10-01 21:52 UTCEchelonGraph re-scored
  51. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  52. 2026-09-30 18:47 UTCEchelonGraph re-scored
  53. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  54. 2026-09-29 16:34 UTCEchelonGraph re-scored
  55. 2026-09-29 15:53 UTCEchelonGraph re-scored
  56. 2026-09-29 15:28 UTCEchelonGraph re-scoredFirst assessed: 6.3 MEDIUM
  57. 2026-09-29 15:28 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-102598?
CVE-2026-102598 is a medium-severity vulnerability; its CVE record was published on September 29, 2026. Werkzeug is a comprehensive WSGI web application library. Prior to 3.1.9, the safe_join function used by send_from_directory can allow a NUL: special-device path because safe_join checks the Windows device name without first removing an empty NTFS ADS marker. The trigger is that an application runs…
When was the CVE record for CVE-2026-102598 published?
The CVE record for CVE-2026-102598 was published on September 29, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 30, 2026; the record at its source may have been updated since.
Is CVE-2026-102598 actively exploited?
CVE-2026-102598 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (31st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-102598?
CVE-2026-102598 has a CVSS base score of 6.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-102598?
A fix for CVE-2026-102598 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-102598 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-102598

Explore →

Is Your Infrastructure Affected by CVE-2026-102598?

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