Legacy Update is a tool for activating and installing updates on legacy Windows PCs. Legacy Update 1.12.0 through 1.13.1 contains an origin validation error in the IsPermitted method of its ActiveX control. After successfully reading the hosting document's hostname, a hostname that is not on the permitted list falls through without setting E_ACCESSDENIED, causing IsPermitted to return S_OK. An attacker who induces a user to visit a malicious webpage in Internet Explorer can invoke the control to enumerate update and system information, install updates without consent, display dialogs, or restart the computer when a reboot is pending. This issue was fixed in Legacy Update 1.13.2.
CVE-2026-97381
CRITICALPre-NVD 9.99.9
EchelonGraph scoreLOW confidence
This critical-severity CVE scores 9.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). No GitHub Security Advisory CVSS is on record for this CVE.
Triggered by: Headline CVSS from a secondary CVSS source
Sources: a secondary CVSS source
9.9EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 9.9Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 9.9
- EG Score
- 9.9CRITICALlow confidence
- EG Risk
- 45EG Risk 45/100
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)Severity99% × 45%The EG Score, 9.9 of 10.Exploitation0% × 40%No KEV listing, EG-KEV tier or EPSS 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: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- —
- EPSS %ILE
- —
- 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 available. 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.
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
October 13, 2026
Last Modified
October 13, 2026
Advisory Details (4)
Auto-updated Oct 14, 2026Patch available. Sources: github, github_commit, github_release.
GitHub advisoryMentions a patch (unverified)
Legacy Update ActiveX control IsPermitted() incorrectly accepts any hostname · Advisory · LegacyUpdate/LegacyUpdate · GitHub
https://github.com/LegacyUpdate/LegacyUpdate/security/advisories/GHSA-f4g7-4gmx-jfgfGitHub release Patch Available
1.13.2
Patch available: LegacyUpdate/LegacyUpdate v1.13.2.0
https://github.com/LegacyUpdate/LegacyUpdate/releases/tag/v1.13.2.0GitHub commit Patch Available
commit ae1c46c97f39 (LegacyUpdate/LegacyUpdate)
Patch available: LegacyUpdate/LegacyUpdate v1.12.0.0 (contains commit ae1c46c97f39)
https://github.com/LegacyUpdate/LegacyUpdate/commit/ae1c46c97f39a55a1937784d9f9beb30aa9147fdGitHub commit Patch Available
commit 7d62f0bfaa77 (LegacyUpdate/LegacyUpdate)
Patch available: LegacyUpdate/LegacyUpdate v1.13.2.0 (contains commit 7d62f0bfaa77)
https://github.com/LegacyUpdate/LegacyUpdate/commit/7d62f0bfaa770d74cd6e2cb0bac9c1907df48033Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 3× in last 7d / 3× 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 22:26 UTCEG score recompute
- 2026-10-13 21:21 UTCEG score recomputeFirst assessed: 9.9 CRITICAL
- 2026-10-13 21:19 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(4)
What is CVE-2026-97381?
CVE-2026-97381 is a critical-severity vulnerability; its CVE record was published on October 13, 2026. Legacy Update is a tool for activating and installing updates on legacy Windows PCs. Legacy Update 1.12.0 through 1.13.1 contains an origin validation error in the IsPermitted method of its ActiveX control. After successfully reading the hosting document's hostname, a hostname that is not on the…
When was the CVE record for CVE-2026-97381 published?
The CVE record for CVE-2026-97381 was published on October 13, 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.
What is the CVSS score of CVE-2026-97381?
CVE-2026-97381 has a CVSS base score of 9.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-97381?
A fix for CVE-2026-97381 is available: update to the fixed version the vendor names in its advisory.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-97381
Is Your Infrastructure Affected by CVE-2026-97381?
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