CVE-2026-7840

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.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total 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

2.63% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 84.3% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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

Modified. NVD last modified this record on 2026-07-09.

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

2026-07-01 03:33Z2 MO AGO

Last updated

2026-07-09 04:36Z1 MO AGO

Reserved

2026-05-05

Assigning CNA

securin

Record state

PUBLISHED

Severity

Critical (CVSS 9.3)

CNA CVSS vector

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

Weaknesses

• CWE-787Out-of-bounds WriteBase

Data version

5.2

Document digest

7ecae83a9e5e4236c3aa44e0eedb1c1349b8a61c37fdeab38448321fa0276a8d

• uvnc.comUltraVNC project pagehttps://uvnc.com/vendor-advisory
• github.comUltraVNC source repositoryhttps://github.com/ultravnc/UltraVNCproduct
• www.securin.iohttps://www.securin.io/zero-days/cve-2026-7840-pre-auth-global-buffer-overflow-repeater-http-admin-ultravnc