CVE-2026-78189

CRITICALPre-NVD 9.89.8
EchelonGraph scoreHIGH confidence

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

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-10-31. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory

Also known asEUVD-2026-114715 (ENISA EUVD) · GHSA-vhwh-fhm6-mq7v (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 9.8Exploit: None knownExposed services: Not assessed

Upgrade to WebDyne 3.022 or later (from the CVE record's solution, CPAN Security Group) — apply it.

WebDyne versions from 3.007 before 3.022 for Perl execute .psp files outside the document root via path traversal in the PSGI API route fallback.

When a request matches no file, the PSGI handler retries it as an API route through api_filename. That keeps .. segments in the request path and only checks that the joined path starts with the document root, which a request for /../private passes.

A remote attacker can run the embedded Perl in any .psp file the server can read, such as one uploaded to a directory outside the document root.

CVSS v3
9.8
EG Score
9.8CRITICALhigh confidence
EG Risk
59
EG Risk 59/100

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)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.6% × 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 total (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: Upgrade to WebDyne 3.022 or later (from the CVE record's solution, CPAN Security Group). Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.6%
EPSS %ILE
49th
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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). 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: 3 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).

Upgrade to WebDyne 3.022 or later (from the CVE record's solution, CPAN Security Group). 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 total (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)3 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 total (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

October 31, 2026

Last Modified

November 6, 2026

Advisory Details (1)

Auto-updated Nov 7, 2026
Fix named in the CVE record's solution (CPAN Security Group).

Vendor Advisories for CVE-2026-78189(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 18× in last 7d / 27× 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 v3 → 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 10:10 UTCEchelonGraph re-scored
  2. 2026-11-13 10:10 UTCGHSA enrichmentGHSA-vhwh-fhm6-mq7v · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  4. 2026-11-12 10:52 UTCEchelonGraph re-scored
  5. 2026-11-12 10:52 UTCGHSA enrichmentGHSA-vhwh-fhm6-mq7v · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  7. 2026-11-11 11:37 UTCEchelonGraph re-scored
  8. 2026-11-11 11:37 UTCGHSA enrichmentGHSA-vhwh-fhm6-mq7v · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  10. 2026-11-10 12:23 UTCEchelonGraph re-scored
  11. 2026-11-10 12:23 UTCGHSA enrichmentGHSA-vhwh-fhm6-mq7v · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-11-09 16:36 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  13. 2026-11-09 13:10 UTCEchelonGraph re-scored
  14. 2026-11-09 13:10 UTCGHSA enrichmentGHSA-vhwh-fhm6-mq7v · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-11-08 16:40 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  16. 2026-11-08 13:54 UTCEchelonGraph re-scored
  17. 2026-11-08 13:53 UTCGHSA enrichmentGHSA-vhwh-fhm6-mq7v · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  19. 2026-11-07 14:40 UTCEchelonGraph re-scored
  20. 2026-11-07 14:40 UTCGHSA enrichmentGHSA-vhwh-fhm6-mq7v · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-11-06 18:55 UTCOSV refresh
  22. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  23. 2026-11-06 15:27 UTCGHSA enrichmentGHSA-vhwh-fhm6-mq7v
  24. 2026-11-06 14:43 UTCEchelonGraph re-scoredFirst assessed: 9.8 CRITICAL
  25. 2026-11-06 14:43 UTCGHSA enrichmentGHSA-vhwh-fhm6-mq7v
Show 12 more
  1. 2026-11-06 14:42 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  2. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  3. 2026-11-04 16:36 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  4. 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  5. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  6. 2026-11-02 16:32 UTCEchelonGraph re-scored
  7. 2026-11-02 16:32 UTCGHSA enrichmentGHSA-vhwh-fhm6-mq7v
  8. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  9. 2026-10-31 16:02 UTCENISA EUVD ID recordedEUVD-2026-114715 · Source: ENISA EUVD
  10. 2026-10-31 15:26 UTCNVD update
  11. 2026-10-31 14:39 UTCEchelonGraph re-scored
  12. 2026-10-31 14:38 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-78189?
CVE-2026-78189 is a critical-severity vulnerability; its CVE record was published on October 31, 2026. WebDyne versions from 3.007 before 3.022 for Perl execute .psp files outside the document root via path traversal in the PSGI API route fallback. When a request matches no file, the PSGI handler retries it as an API route through api_filename. That keeps .. segments in the request path and only…
When was the CVE record for CVE-2026-78189 published?
The CVE record for CVE-2026-78189 was published on October 31, 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 November 6, 2026; the record at its source may have been updated since.
Is CVE-2026-78189 actively exploited?
CVE-2026-78189 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (49th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-78189?
CVE-2026-78189 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-78189?
The CVE record's solution for CVE-2026-78189, written by its CNA CPAN Security Group, names the fix: "Upgrade to WebDyne 3.022 or later." The vendor advisories EchelonGraph has for CVE-2026-78189 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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