CVE-2026-108390

CRITICALPre-NVD 9.99.9
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.7% (51st 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
Trending — 3 sources updated this weekElevated
9.9EG
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).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 9.9Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Hestia Control Panel is a lightweight and powerful control panel for the modern web. From version 1.9.7 through 1.10.4, update_object_value() in func/main.sh does not escape single quotes when writing a custom document-root value to a user's web.conf file, allowing a low-privileged authenticated panel user with a web domain to inject an additional PATH field. When the user invokes the ordinary Search feature, the root-privileged v-search-user-object script loads the forged field through parse_object_kv_list_non_eval(), which permits reserved shell-variable names and globally replaces PATH before invoking column without an absolute path. By placing a malicious column executable in the injected search path, the user can execute arbitrary code as root. This residual vulnerability was introduced when version 1.9.7 replaced the raw eval sink addressed by CVE-2026-84984 with parse_object_kv_list_non_eval(), and it is fixed in version 1.10.5.

CVSS v3
9.9
EG Score
9.9CRITICALmedium confidence
EG Risk
61
EG Risk 61/100

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)
Severity99% × 45%
Impact severity (EG Severity): CVSS 9.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (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: 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
0.7%
EPSS %ILE
51st
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 (9.9): severity, escalated by confirmed exploitation. This CVE's 9.9 is its impact severity (EG Severity), not escalated.

EG Severity
9.9 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-20). 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, Track* at medium and Attend at high mission impact.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: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

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

Exploitation public PoC (CISA Vulnrichment) · Automatable no (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)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (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 14, 2026

Last Modified

October 16, 2026

Advisory Details (3)

Auto-updated Oct 16, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
GitHub advisoryMentions a patch (unverified)🟡 PoC Available

Local Privilege Escalation to Root in HestiaCP via Unescaped Config Write + Unguarded Variable Re-Parse · Advisory · hestiacp/hestiacp · GitHub

https://github.com/hestiacp/hestiacp/security/advisories/GHSA-r9q4-pmcm-5qqf
Web page

CVE-2026-108390: From a Stray Apostrophe to Root — Escalating a Standard HestiaCP Account to Full Server Compromise | Ravindu Lakmina Munaweera - Security Research

https://ravindulakmina.pages.dev/advisories/cve-2026-108390-hestiacp-apostrophe-to-root
GitHub commit Patch Available

commit 4d86018660f3 (hestiacp/hestiacp)

Patch available: hestiacp/hestiacp 1.9.7 (contains commit 4d86018660f3)

https://github.com/hestiacp/hestiacp/commit/4d86018660f35a1d64a0ae819bc5ee700949a287

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 19× 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 it from the CNA feed. 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). Most recent first.

  1. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  2. 2026-10-21 01:40 UTCEG score recompute
  3. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  4. 2026-10-20 00:23 UTCEG score recompute
  5. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  6. 2026-10-18 22:43 UTCEG score recompute
  7. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  8. 2026-10-18 05:07 UTCEG score recompute
  9. 2026-10-17 21:24 UTCEG score recompute
  10. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  11. 2026-10-16 20:06 UTCEG score recompute
  12. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  13. 2026-10-16 00:19 UTCEG score recompute
  14. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  15. 2026-10-14 18:46 UTCEG score recompute
  16. 2026-10-14 18:25 UTCEG score recompute
  17. 2026-10-14 18:01 UTCEG score recompute
  18. 2026-10-14 17:25 UTCEG score recomputeFirst assessed: 9.9 CRITICAL
  19. 2026-10-14 17:24 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-108390?
CVE-2026-108390 is a critical-severity vulnerability; its CVE record was published on October 14, 2026. Hestia Control Panel is a lightweight and powerful control panel for the modern web. From version 1.9.7 through 1.10.4, updateobjectvalue() in func/main.sh does not escape single quotes when writing a custom document-root value to a user's web.conf file, allowing a low-privileged authenticated…
When was the CVE record for CVE-2026-108390 published?
The CVE record for CVE-2026-108390 was published on October 14, 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 October 16, 2026; the record at its source may have been updated since.
Is CVE-2026-108390 actively exploited?
CVE-2026-108390 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (51st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-108390?
CVE-2026-108390 has a CVSS base score of 9.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-108390?
A fix for CVE-2026-108390 is available: update to the fixed version the vendor names in its advisory.

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