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Vulnerability record/PUBLISHED/Published May 26, 2026 14:08:47 UTC

CVE-2026-40033

FreeRDP before 3.26.0 contains a heap-buffer-overflow vulnerability in gdi_CacheToSurface that allows remote attackers to write out-of-bounds heap memory. The vulnerability occurs because rectangle validation clamps coordinates to UINT16_MAX but performs copy operations using unclamped cache entry dimensions, enabling malicious RDP servers to trigger large out-of-bounds writes and potentially achieve remote code execution or client crash.

Base score8.6/ 10
SeverityHighCVSS 4.0

Exploitability / impact

CVSS metric breakdown

Vector-derived attributes
Base severityHigh
Attack vectorNetworkAV
Attack complexityLowAC
Attack requirementsNoneAT
Privileges requiredNonePR
User interactionPassiveUI
Vulnerable system confidentialityHighVC
Vulnerable system integrityHighVI
Vulnerable system availabilityHighVA
Subsequent system confidentialityNoneSC
Subsequent system integrityNoneSI
Subsequent system availabilityNoneSA
CVSS vector stringCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.

Record context

CVE Numbering AuthorityVulnCheck
Last updatedNov 8, 2026 14:02:45 UTC
PublishedMay 26, 2026 14:08:47 UTC
ReservedApr 8, 2026 13:36:55 UTC

Credits

  • kevin-valerio