CVE-2026-66749

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.43% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 37.5% of scored records. A rank, not a probability.

NVD base score

7.1 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Deferred. NVD last modified this record on 2026-10-24.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-07-28 15:30Z3 MO AGO

Last updated

2026-07-28 16:43Z3 MO AGO

Reserved

2026-07-27

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

High (CVSS 7.1)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Weaknesses

• CWE-476NULL Pointer DereferenceBase

Data version

5.2

Document digest

092ad9ea43db1fcab5a379f75ad0ffd9fd0aa5ae0037bc31326001523ea96552

• github.comResearcher Disclosurehttps://github.com/theopaid/Unchecked-Room-Lookup-Leads-to-Server-Crash-Let-s-Chat-technical-descriptionexploit
• www.vulncheck.comhttps://www.vulncheck.com/advisories/let-s-chat-denial-of-service-via-null-dereference-in-room-lookupthird-party-advisory