Quick answers
- Is CVE-2026-7828 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-7828 being exploited in the wild.
- How severe is CVE-2026-7828?
- Medium severity, with a CVSS score of 5.3, published 1 July 2026.
- Which products and versions are affected?
- UltraVNC Repeater through 1.8.2.2.
- Is there a fix for CVE-2026-7828?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-7828 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-7828?
- Check whether you run UltraVNC Repeater at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
An integer overflow exists in the win_log() function within repeater/webgui/settings.c:336 of UltraVNC Repeater. The vulnerability occurs when the function calculates the memory required for a new log entry using malloc(sizeof(struct LIST) + strlen(line)). If the URI-derived 'line' string is sufficiently long, the addition overflows, resulting in a heap allocation smaller than the actual data. A subsequent strcpy() operation then writes the full string into the undersized buffer, causing a heap buffer overflow. While the overflow is currently bounded by the 153,600-byte HTTP receive buffer (WI_RXBUFSIZE), it allows for a partial heap write by a remote unauthenticated attacker. Version 1.8.2.4 appears to be available as a newer release, though the advisory specifically notes the flaw through 1.8.2.2.
Affected products
- UltraVNC UltraVNC Repeater through 1.8.2.2
Timeline
- 2026-07-01: advisory: CVE-2026-7828 published by NVD