Uncontrolled eviction in the browser session table of the REST API in Progressive Robot hMailServer 6.2.28 through 6.3.5 allows a remote authenticated user to end other users' sessions. The table of browser sessions, shared by every account, the server administrator and support sessions, dropped its least recently used session whenever it was full, whoever it belonged to, and placed no limit on how many sessions one account could hold. A user who repeatedly signs in with their own mailbox password can therefore keep the table full and sign out every webmail and administration session that is idle for more than a short time, for as long as they continue.
CVE-2026-107586
MEDIUMPre-NVD 4.34.3—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 4.3 from GitHub Security Advisory published 2026-10-08. A secondary CVSS source baseline 4.3; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 4.3Exploit: None knownExposed services: Not assessed
No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.
- CVSS v3
- 4.3
- EG Score
- 4.3MEDIUMhigh confidence
- EG Risk
- 19EG Risk 19/100CISA 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 computedSeverity43% × 45%Exploitation0% × 40%Automatability0% × 15%CISA SSVC: Track at every mission impact level.Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix. - EPSS PROB
- 0.3%
- EPSS %ILE
- 25th
- KEV
- Not listed
CISA SSVCTrack at every mission impact level.
No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
Exploitation none (CISA Vulnrichment) · Automatable no (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
October 8, 2026
Last Modified
October 8, 2026
Advisory Details (2)
Auto-updated Oct 8, 2026No fix on record yet.
generic
REST API browser sessions: one account signing in over and over signed every other idle webmail and administration session out (#62) · Issues · hmailserver / hMailServer · GitLab
https://gitlab.com/hmailserver/hmailserver/-/work_items/62generic
hMailServer 6.3.6 · hmailserver / hMailServer · GitLab
https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6Vendor Advisories for CVE-2026-107586(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 11× in last 7d / 11× 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.
- 2026-10-09 22:39 UTCEG score recompute
- 2026-10-09 22:39 UTCGHSA enrichment
- 2026-10-09 20:06 UTCEPSS rescore
- 2026-10-08 21:17 UTCGHSA enrichment
- 2026-10-08 20:20 UTCEG score recompute
- 2026-10-08 20:20 UTCGHSA enrichment
- 2026-10-08 19:25 UTCEG score recompute
- 2026-10-08 19:25 UTCGHSA enrichment
- 2026-10-08 15:20 UTCEG score recompute
- 2026-10-08 15:17 UTCEG score recompute
- 2026-10-08 15:16 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-107586?
CVE-2026-107586 is a medium vulnerability published on October 8, 2026. Uncontrolled eviction in the browser session table of the REST API in Progressive Robot hMailServer 6.2.28 through 6.3.5 allows a remote authenticated user to end other users' sessions. The table of browser sessions, shared by every account, the server administrator and support sessions, dropped…
When was CVE-2026-107586 disclosed?
CVE-2026-107586 was first published on October 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-107586 actively exploited?
CVE-2026-107586 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (25th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-107586?
CVE-2026-107586 has a CVSS base score of 4.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-107586?
No fix for CVE-2026-107586 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-107586 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-107586
Is Your Infrastructure Affected by CVE-2026-107586?
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