Incorrect default permissions in the Windows installer of Progressive Robot hMailServer 6.3.7 allow a local authenticated user to run code as the administrator who runs setup, when the server is installed into a program folder that is already there and that accounts other than the administrators could write, such as a folder made beforehand at the root of a drive, or when such an installation is upgraded or repaired. 6.3.7 fixed CVE-2026-107571 by giving the program folder, Bin and ControlPanel permissions that only administrators may change, but for a folder that is already there it does so only at the end of setup: setup first copies the programs into Bin, which every user may still write, and runs programs from Bin with the administrator's elevated rights, registering the service among them, before that hardening, so that a library another account places in Bin meanwhile is loaded in place of the system's. A handle an account opened on such a folder while it could write it keeps that access after the hardening. The default installation under Program Files, whose folders give ordinary users read and execute only, is not affected.
CVE-2026-126622
“—” beside the score: it is equal to the CVSS score beside it.
Score 7.3 from GitHub Security Advisory (severity: HIGH) published 2026-11-11. A secondary CVSS source baseline 7.3; sources differ by 0.0.
Also known asEUVD-2026-123327 (ENISA EUVD) · GHSA-45pg-vr27-cp42 (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
Upgrade to hMailServer 6.3.8, whose setup hardens a program folder, Bin and ControlPanel that are already there before it stops the service, copies a file or runs a program of the installation, reading each through a ha… (from the CVE record's solution, GitLab Inc.) — apply it.
- CVSS v3
- 7.3
- EG Score
- 7.3HIGHhigh confidence
- EG Risk
- 33EG Risk 33/100
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)Severity73% × 45%Impact severity (EG Severity): CVSS 7.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.1% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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 hMailServer 6.3.8, whose setup hardens a program folder, Bin and ControlPanel that are already there before it stops the service, copies a file or runs a program of the installation, reading each through a ha… (from the CVE record's solution, GitLab Inc.). Apply it within your standard update timelines. - EPSS PROB
- 0.1%
- EPSS %ILE
- 2nd
- 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 (7.3): severity, escalated by confirmed exploitation. This CVE's 7.3 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.3 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.1% 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; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade 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; Track* at high (mission-essential systems).
Upgrade to hMailServer 6.3.8, whose setup hardens a program folder, Bin and ControlPanel that are already there before it stops the service, copies a file or runs a program of the installation, reading each through a ha… (from the CVE record's solution, GitLab Inc.). Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” 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
November 11, 2026
Last Modified
November 12, 2026
Advisory Details (3)
Auto-updated Nov 11, 2026hMailServer 6.3.8 · hmailserver / hMailServer · GitLab
https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.8Windows installer: an installation at a drive's root leaves the program folder and Bin writable by local users, a local privilege escalation (6.0.0-6.3.6) (#78) · Issues · hmailserver / hMailServer · GitLab
https://gitlab.com/hmailserver/hmailserver/-/work_items/78Vendor Advisories for CVE-2026-126622(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 6× in last 7d / 6× 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.
- 2026-11-12 19:08 UTCEchelonGraph re-scored
- 2026-11-12 19:08 UTCGHSA enrichmentGHSA-45pg-vr27-cp42 · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
- 2026-11-11 16:38 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
- 2026-11-11 09:46 UTCEchelonGraph re-scored
- 2026-11-11 09:46 UTCGHSA enrichmentGHSA-45pg-vr27-cp42 · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-11-11 09:27 UTCEchelonGraph re-scored
- 2026-11-11 09:00 UTCENISA EUVD ID recordedEUVD-2026-123327 · Source: ENISA EUVD
- 2026-11-11 08:39 UTCEchelonGraph re-scoredFirst assessed: 7.3 HIGH
- 2026-11-11 08:39 UTCMITRE cvelistV5first tracked
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Frequently asked(5)
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Dependency Blast Radius
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