A vulnerability has been found in InstantSoft icms2 up to 2.18.2. This issue affects the function index of the file templates/default/controllers/messages/index.tpl.php of the component Private Message Handler. Such manipulation of the argument nickname leads to cross site scripting. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The name of the patch is 3a1ec8fcb073a46d06a2ab83bc2bf68225834281. It is best practice to apply a patch to resolve this issue.
CVE-2026-108566
LOWPre-NVD 3.53.5Trending — 5 sources updated this weekElevatedEG-KEV Tier 3: ElevatedEG-KEV is EchelonGraph's own tiering of exploitation signals from CISA KEV, CISA's SSVC data (Vulnrichment), ransomware data, public exploit-code references and EPSS.Tier 3 is not evidence of exploitation. It means public exploit code is referenced, or CISA's SSVC data says "public PoC", or EPSS ranks the CVE in the top 5%.Signals for this CVE: CISA's SSVC exploitation value: public PoC.EchelonGraph confidence 38%: a heuristic from the tier and the number of signals, not a measured probability.
EchelonGraph scoreHIGH confidence
“—” beside the score: it is equal to the CVSS score beside it.
Score 3.5 from GitHub Security Advisory (severity: LOW) published 2026-10-11. A secondary CVSS source baseline 3.5; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
3.5EG
EchelonGraph verdictPlan mitigationRemediate within your standard update timelines (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: 0.2%CVSS: 3.5Exploit: No code on recordExposed services: Not assessed
A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).
- CVSS v3
- 3.5
- EG Score
- 3.5LOWhigh confidence
- EG Risk
- 32EG Risk 32/100
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 (value × EchelonGraph’s weight)Severity35% × 45%The EG Score, 3.5 of 10.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 or medium mission impact; Track* at high (mission-essential systems).Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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 referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation. - EPSS PROB
- 0.2%
- EPSS %ILE
- 8th
- KEV
- Not listed
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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)60 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 partial (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 11, 2026
Last Modified
October 13, 2026
References (6)
- cna@vuldbhttps://github.com/instantsoft/icms2/Product
- cna@vuldbhttps://github.com/instantsoft/icms2/commit/3a1ec8fcb073a46d06a2ab83bc2bf68225834281Patch
- cna@vuldbhttps://vuldb.com/cve/CVE-2026-108566Third Party Advisory
- cna@vuldb · CISA-ADPhttps://vuldb.com/submit/954247Third Party Advisory · Exploit
- cna@vuldbhttps://vuldb.com/vuln/416223VDB Entry · Technical Description
- cna@vuldbhttps://vuldb.com/vuln/416223/ctiSignature · Permissions Required
Vendor Advisories for CVE-2026-108566(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 17× in last 7d / 17× 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.
- 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
- 2026-10-13 13:58 UTCGHSA enrichmentGHSA-j944-2cmv-5vxf · GitHub severity LOW · GitHub CVSS 3.5
- 2026-10-13 13:25 UTCEG score recompute
- 2026-10-13 13:25 UTCGHSA enrichmentGHSA-j944-2cmv-5vxf · GitHub severity LOW · GitHub CVSS 3.5
- 2026-10-13 13:24 UTCNVD updateCVSS v4 → 2
- 2026-10-13 13:10 UTCEG score recompute
- 2026-10-13 13:10 UTCGHSA enrichmentGHSA-j944-2cmv-5vxf · GitHub severity LOW · GitHub CVSS 3.5
- 2026-10-12 16:38 UTCEG score recompute
- 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
- 2026-10-11 20:13 UTCEG score recompute
- 2026-10-11 18:26 UTCEG score recompute
- 2026-10-11 14:59 UTCEG score recompute
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.3% · 26th percentile
- 2026-10-11 10:23 UTCEG score recompute
- 2026-10-11 10:22 UTCNVD updateCVSS v4 → 2
- 2026-10-11 09:33 UTCEG score recomputeFirst assessed: 3.5 LOW
- 2026-10-11 09:31 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-108566?
CVE-2026-108566 is a low-severity vulnerability; its CVE record was published on October 11, 2026. A vulnerability has been found in InstantSoft icms2 up to 2.18.2. This issue affects the function index of the file templates/default/controllers/messages/index.tpl.php of the component Private Message Handler. Such manipulation of the argument nickname leads to cross site scripting. The attack can…
When was the CVE record for CVE-2026-108566 published?
The CVE record for CVE-2026-108566 was published on October 11, 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 13, 2026; the record at its source may have been updated since.
Is CVE-2026-108566 actively exploited?
CVE-2026-108566 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (8th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-108566?
CVE-2026-108566 has a CVSS base score of 3.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-108566?
A fix for CVE-2026-108566 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation. The vendor advisories EchelonGraph has for CVE-2026-108566 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-108566
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