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CVE Vulnerability Details :
CVE-2026-40033
PUBLISHED
More InfoOfficial Page
Assigner-VulnCheck
Assigner Org ID-83251b91-4cc7-4094-a5c7-464a1b83ea10
View Known Exploited Vulnerability (KEV) details
Published At-26 May, 2026 | 14:08
Updated At-27 Jul, 2026 | 12:05
Rejected At-
▼CVE Numbering Authority (CNA)
FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass

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.

Affected Products
Vendor
FreeRDPFreeRDP
Product
FreeRDP
Default Status
unaffected
Versions
Affected
  • From 0 before 3.26.0 (semver)
Unaffected
  • 3.26.0 (semver)
Problem Types
TypeCWE IDDescription
CWECWE-122Heap-based Buffer Overflow
Type: CWE
CWE ID: CWE-122
Description: Heap-based Buffer Overflow
Metrics
VersionBase scoreBase severityVector
4.08.6HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
3.18.8HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Version: 4.0
Base score: 8.6
Base severity: HIGH
Vector:
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Version: 3.1
Base score: 8.8
Base severity: HIGH
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions

Configurations

Workarounds

Exploits

Credits

reporter
kevin-valerio
Timeline
EventDate
Replaced By

Rejected Reason

References
HyperlinkResource
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff
vendor-advisory
https://github.com/FreeRDP/FreeRDP/pull/12713
issue-tracking
https://github.com/FreeRDP/FreeRDP/commit/d7508ebcd82842a691ae4941e5104d14240a89ae
patch
https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypass
third-party-advisory
Hyperlink: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff
Resource:
vendor-advisory
Hyperlink: https://github.com/FreeRDP/FreeRDP/pull/12713
Resource:
issue-tracking
Hyperlink: https://github.com/FreeRDP/FreeRDP/commit/d7508ebcd82842a691ae4941e5104d14240a89ae
Resource:
patch
Hyperlink: https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypass
Resource:
third-party-advisory
▼Authorized Data Publishers (ADP)
1. CISA ADP Vulnrichment
Affected Products
Metrics
VersionBase scoreBase severityVector
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions

Configurations

Workarounds

Exploits

Credits

Timeline
EventDate
Replaced By

Rejected Reason

References
HyperlinkResource
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff
exploit
Hyperlink: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff
Resource:
exploit
2. freerdp: FreeRDP: Remote code execution via heap-buffer-overflow in gdi_CacheToSurface

A flaw was found in FreeRDP.If a user connects to a malicious Remote Desktop (RDP) server, a security flaw in FreeRDP could cause the application to crash or allow the server to run unauthorized code on the user's system.

Affected Products
Vendor
Red Hat, Inc.Red Hat
Product
Red Hat Enterprise Linux 10
Collection URL
https://access.redhat.com/downloads/content/package-browser/
Package Name
freerdp
CPEs
  • cpe:/o:redhat:enterprise_linux:10.2
Default Status
affected
Versions
Unaffected
  • From 2:3.10.3-12.el10_2.6 before * (rpm)
Vendor
Red Hat, Inc.Red Hat
Product
Red Hat Enterprise Linux 6
Collection URL
https://access.redhat.com/downloads/content/package-browser/
Package Name
freerdp
CPEs
  • cpe:/o:redhat:enterprise_linux:6
Default Status
unknown
Vendor
Red Hat, Inc.Red Hat
Product
Red Hat Enterprise Linux 7
Collection URL
https://access.redhat.com/downloads/content/package-browser/
Package Name
freerdp
CPEs
  • cpe:/o:redhat:enterprise_linux:7
Default Status
unaffected
Vendor
Red Hat, Inc.Red Hat
Product
Red Hat Enterprise Linux 8
Collection URL
https://access.redhat.com/downloads/content/package-browser/
Package Name
freerdp
CPEs
  • cpe:/o:redhat:enterprise_linux:8
Default Status
unaffected
Vendor
Red Hat, Inc.Red Hat
Product
Red Hat Enterprise Linux 9
Collection URL
https://access.redhat.com/downloads/content/package-browser/
Package Name
freerdp
CPEs
  • cpe:/o:redhat:enterprise_linux:9
Default Status
affected
Problem Types
TypeCWE IDDescription
CWECWE-787Out-of-bounds Write
Type: CWE
CWE ID: CWE-787
Description: Out-of-bounds Write
Metrics
VersionBase scoreBase severityVector
3.18.8HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Version: 3.1
Base score: 8.8
Base severity: HIGH
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Metrics Other Info
Red Hat severity rating
value:
Important
namespace:
https://access.redhat.com/security/updates/classification/
Impacts
CAPEC IDDescription
Solutions

RHSA-2026:46393: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)

RHSA-2026:36203: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)

Configurations

Workarounds

To mitigate this issue, users should avoid connecting to untrusted or unknown Remote Desktop Protocol (RDP) servers. Restricting FreeRDP client usage to only known and trusted RDP servers can reduce the risk of exploitation.

Exploits

Credits

Timeline
EventDate
Reported to Red Hat.2026-05-26 15:01:26
Made public.2026-05-26 14:08:47
Event: Reported to Red Hat.
Date: 2026-05-26 15:01:26
Event: Made public.
Date: 2026-05-26 14:08:47
Replaced By

Rejected Reason

References
HyperlinkResource
https://access.redhat.com/security/cve/CVE-2026-40033
vdb-entry
x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2481473
issue-tracking
x_refsource_REDHAT
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40033.json
x_sadp-csaf-vex
https://access.redhat.com/errata/RHSA-2026:46393
vendor-advisory
x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:36203
vendor-advisory
x_refsource_REDHAT
Hyperlink: https://access.redhat.com/security/cve/CVE-2026-40033
Resource:
vdb-entry
x_refsource_REDHAT
Hyperlink: https://bugzilla.redhat.com/show_bug.cgi?id=2481473
Resource:
issue-tracking
x_refsource_REDHAT
Hyperlink: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40033.json
Resource:
x_sadp-csaf-vex
Hyperlink: https://access.redhat.com/errata/RHSA-2026:46393
Resource:
vendor-advisory
x_refsource_REDHAT
Hyperlink: https://access.redhat.com/errata/RHSA-2026:36203
Resource:
vendor-advisory
x_refsource_REDHAT
Details not found