CVE-2026-7838

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 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

1.86% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 78.7% of scored records. A rank, not a probability.

NVD base score

8.7 (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:P/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 2026-10-25.

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 03:33Z4 MO AGO

Last updated

2026-07-09 04:35Z3 MO AGO

Reserved

2026-05-05

Assigning CNA

securin

Record state

PUBLISHED

Severity

High (CVSS 8.7)

CNA CVSS vector

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

Weaknesses

• CWE-190Integer Overflow or WraparoundBase
• CWE-787Out-of-bounds WriteBase

Data version

5.2

Document digest

ceb1fc41a253d7f66a5975445793b6e44ec9b49840aa96d1fd76a18466c5caa0

• 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-2026-7838-heap-overflow-viewer-reasonlen-integer-overflow-ultravnc