← Vulnerability feed

Vulnerability record · CVE-2019-25600 · published 22 March 2026

CVE-2019-25600: Out-of-bounds write vulnerability

UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer.

7.1 CVSS 4.0 High EPSS 0.69% · top 49.2% CWE-787 · Out-of-bounds write Deferred
7.1CVSS 4.0 base score
0.69%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

Description

UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/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:

References

LinkTags
https://www.exploit-db.com/exploits/46702
https://www.uvnc.com/
https://www.uvnc.com/downloads/ultravnc/126-download-ultravnc-1224.html
https://www.vulncheck.com/advisories/ultravnc-viewer-denial-of-service-via-buffer-overflow

Track CVE-2019-25600 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.8CVE-2026-53266Linux kernel ebtables SNAT out-of-bounds write in ARP rewriteThe ebtables SNAT target rewrites the ARP sender hardware address via skb_store_bits() without first making that range writable. When the ARP SHA byt…KEVEPSS 0.65%analysed8.8CVE-2026-87491Google Chrome V8 out-of-bounds write enables sandbox code executionChrome before 153.0.8010.36 contains an out-of-bounds write in the V8 JavaScript engine. A crafted HTML page can trigger the memory corruption, and b…KEVEPSS 3.1%analysed9.8CVE-2025-25249Fortinet FortiOS and FortiSwitchManager heap buffer overflow via crafted packetsA heap-based buffer overflow (CWE-122/CWE-787) in Fortinet FortiOS 6.4 through 7.6.3 and FortiSwitchManager 7.0 through 7.2.6 lets an unauthenticated…KEVEPSS 3.9%analysed7.8CVE-2026-53362Linux kernel IPv6 UDP paged allocation out-of-bounds write__ip6_append_data() in the Linux kernel mis-accounts fraggap on the paged-allocation path, leaving the linear skb area undersized while pagedlen is o…KEVEPSS 0.71%analysed7.8CVE-2022-0995Linux kernel watch_queue out-of-bounds writeThe Linux kernel's watch_queue event notification subsystem contains an out-of-bounds write (CWE-787) that can overwrite kernel state. A local user c…KEVEPSS 8.8%analysed8.8CVE-2026-11645Google Chrome V8 out-of-bounds read and write enables sandbox code executionGoogle Chrome before 149.0.7827.103 contains an out-of-bounds read and write in the V8 JavaScript engine. A crafted HTML page can trigger the memory …KEVEPSS 2.2%analysed9.3CVE-2026-0300PAN-OS User-ID Authentication Portal buffer overflow allows root code executionA buffer overflow (out-of-bounds write, CWE-787) in the User-ID Authentication Portal (Captive Portal) service of Palo Alto Networks PAN-OS lets an u…KEVEPSS 32%analysed8.8CVE-2026-3909Google Chrome Skia out-of-bounds write via crafted HTML pageChrome's Skia graphics library contains an out-of-bounds write (CWE-787) that a remote attacker can trigger with a crafted HTML page. It is fixed in …KEVEPSS 0.70%analysed

Source: NIST National Vulnerability Database (record CVE-2019-25600), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.