Linked CVE review

Deploy Microsoft Windows security update KB5123303

Linked CVEs: 3
Confirmed exploited: 0
PoC or lab evidence: 0
Maximum CVSS: 7.9

Evidence is kept separate

Confirmed exploitation, public exploit material, EPSS probability and CVSS severity answer different questions. “No confirmation recorded” means the checked sources do not currently confirm exploitation. It is not proof that exploitation has not occurred.

3 of 3 linked CVEs shown

Confirmed exploitedCVSS above 9.0

CVE and description	Severity	Exploit reality	Forecast and access	Remediation
CVE-2026-66799 Scheduled assessment Windows Key Guard Elevation of Privilege Vulnerability Heap-based buffer overflow in Windows Key Guard allows an authorized attacker to elevate privileges locally.	7.8 · CVSS 3.1 · HighSource: CNA	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 0.33% · 24.6th percentileForecast date: 2026-10-07LOCAL · LOW complexity · LOW privileges · NONE user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Patch available. Before you apply this update, make sure all previously released errata that are relevant to your system are applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
CVE-2026-6726 Scheduled assessment An information leakage vulnerability in the TCG TPM 2.0 reference code. An information leakage vulnerability was reported in the TCG TPM 2.0 reference code that could allow a local attacker with elevated privileges to obtain a credential from a TPM-aware CA for a falsified TPM key (such as an Attestation Key, DevID Key or TLS authentication key) and falsify other TPM 2.0 attestations with this key. See also TCG VRT0010.	7.9 · CVSS 3.1 · HighSource: CISA ADP	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 0.19% · 8.1th percentileForecast date: 2026-10-07LOCAL · LOW complexity · HIGH privileges · NONE user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Awaiting fix. No fixed version is explicitly recorded in the structured CVE data.
CVE-2026-6727 Scheduled assessment CVE-2026-6727 A timing side-channel vulnerability exists in the RSA OAEP decryption implementation. A privileged local attacker with access to the TPM command interface may be able to exploit timing differences to recover information that could allow decryption of ciphertexts encrypted to TPM-managed RSA keys, including the RSA Endorsement Key (EK), including import blobs, credential blobs, and session salts. Under certain conditi	5.9 · CVSS 3.1 · MediumSource: CISA ADP	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 0.15% · 3.8th percentileForecast date: 2026-10-07LOCAL · HIGH complexity · NONE privileges · NONE user interaction	ScheduledMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.Awaiting fix. No fixed version is explicitly recorded in the structured CVE data.