CVE-2026-102598

MEDIUMPre-NVD 6.36.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (28th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 4 sources updated this week
6.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • 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 v3
6.3
EG Score
6.3MEDIUMmedium confidence
EG Risk
43
EG Risk 43/100CISA SSVC

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
Severity63% × 45%
Exploitation0% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
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
28th
KEV
Not listed

CISA SSVCTrack 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). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

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_pr 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 Patch Available

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

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

Vendor Advisories for CVE-2026-102598(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 12× 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. 2026-10-04 02:01 UTCEG score recompute
  2. 2026-10-04 02:01 UTCVendor advisory
  3. 2026-10-03 14:25 UTCEPSS rescore
  4. 2026-10-02 23:57 UTCEG score recompute
  5. 2026-10-01 21:52 UTCEG score recompute
  6. 2026-10-01 19:49 UTCEPSS rescore
  7. 2026-09-30 18:47 UTCEG score recompute
  8. 2026-09-30 15:02 UTCEPSS rescore
  9. 2026-09-29 16:34 UTCEG score recompute
  10. 2026-09-29 15:53 UTCEG score recompute
  11. 2026-09-29 15:28 UTCEG score recompute
  12. 2026-09-29 15:28 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-102598?
CVE-2026-102598 is a medium vulnerability published on September 29, 2026. Werkzeug is a comprehensive WSGI web application library. Prior to 3.1.9, the safejoin function used by sendfromdirectory can allow a NUL: special-device path because safejoin checks the Windows device name without first removing an empty NTFS ADS marker. The trigger is that an application runs on…
When was CVE-2026-102598 disclosed?
CVE-2026-102598 was first published on September 29, 2026, with the most recent update on September 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
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 (28th 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

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