CVE Explorer
CVE-2026-44041
UltraVNC through 1.8.2.2 contains an out-of-bounds read in the wide-string to multibyte conversion helper. In rfb/dh.cpp:204, the vncWc2Mb() function passes a caller-supplied WCHAR pointer to wcslen() before any bounds check. If the caller provides a wide-character buffer that is not properly NUL-terminated, wcslen() reads past the end of the buffer until it encounters a NUL wchar, resulting in an out-of-bounds read. Under typical Win32 API usage this requires an abnormal caller contract. Impact
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"defaultStatus":"unaffected","modules":["winvnc","vncviewer"],"product":"UltraVNC","vendor":"uvnc","versions":[{"lessThanOrEqual":"1.8.2.2","status":"affected","version":"0","versionType":"custom"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:33e8d19f55f5d3cd33f78b0ad9609fb2c344b53f5611da622816fe5a93baa9bf · sha256:dfddad9019afa885… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:33e8d19f55f5d3cd33f78b0ad9609fb2c344b53f5611da622816fe5a93baa9bf · sha256:dfddad9019afa885… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-125","description":"Out-of-bounds Read","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:33e8d19f55f5d3cd33f78b0ad9609fb2c344b53f5611da622816fe5a93baa9bf · sha256:dfddad9019afa885… · /containers/cna/problemTypes/0/descriptions/0
Source references
3 source assertions{"name":"UltraVNC source repository","tags":["product"],"url":"https://github.com/ultravnc/UltraVNC"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:33e8d19f55f5d3cd33f78b0ad9609fb2c344b53f5611da622816fe5a93baa9bf · sha256:dfddad9019afa885… · /containers/cna/references/1
{"name":"UltraVNC project page","tags":["vendor-advisory"],"url":"https://uvnc.com/"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:33e8d19f55f5d3cd33f78b0ad9609fb2c344b53f5611da622816fe5a93baa9bf · sha256:dfddad9019afa885… · /containers/cna/references/0
{"url":"https://www.securin.io/zero-days/cve-2026-44041-vncwc2mb-wcslen-before-bounds-check-ultravnc"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:33e8d19f55f5d3cd33f78b0ad9609fb2c344b53f5611da622816fe5a93baa9bf · sha256:dfddad9019afa885… · /containers/cna/references/2
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.