Answer in brief
CVE-2026-7829 records a High severity (CVSS 7.2) vulnerability in UltraVNC repeater authenticated out-of-bounds write in rule parser via oversized token. The current sources do not mark it as known exploited. The current feed maps uvnc/UltraVNC (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.2. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps uvnc/UltraVNC (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| uvnc/UltraVNCgeneric | 0 | Not reported |
Published upstream
Jul 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 1, 2026
UltraVNC repeater through 1.8.2.2 contains a post-authentication out-of-bounds write in the allow/deny rule parser. In repeater/webgui/settings.c:225-272, after strncpy_s copies a rule token into temp1[rule1] (25-byte destination) or temp2/temp3 (16-byte destination), the code unconditionally writes a NUL terminator at temp1[rule1][len] = 0 without clamping len to the destination size. When an authenticated administrator saves a rule with a token length equal to or greater than the destination size, the NUL byte is written one or more bytes past the end of the stack-allocated array, corrupting adjacent stack data. An attacker who has obtained admin credentials (including via CVE-2026-7839 default password) can trigger this to gain code execution on the repeater host.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-7829 records a High severity (CVSS 7.2) vulnerability in UltraVNC repeater authenticated out-of-bounds write in rule parser via oversized token. The current sources do not mark it as known exploited. The current feed maps uvnc/UltraVNC (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.2. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps uvnc/UltraVNC (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| uvnc/UltraVNCgeneric | 0 | Not reported |
Published upstream
Jul 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 1, 2026
UltraVNC repeater through 1.8.2.2 contains a post-authentication out-of-bounds write in the allow/deny rule parser. In repeater/webgui/settings.c:225-272, after strncpy_s copies a rule token into temp1[rule1] (25-byte destination) or temp2/temp3 (16-byte destination), the code unconditionally writes a NUL terminator at temp1[rule1][len] = 0 without clamping len to the destination size. When an authenticated administrator saves a rule with a token length equal to or greater than the destination size, the NUL byte is written one or more bytes past the end of the stack-allocated array, corrupting adjacent stack data. An attacker who has obtained admin credentials (including via CVE-2026-7839 default password) can trigger this to gain code execution on the repeater host.
Quoted source text, attributed separately from HOL analysis.