← Vulnerability feed

Vulnerability record · CVE-2026-23534 · published 19 January 2026

CVE-2026-23534: Freerdp heap-based buffer overflow vulnerability

Freerdp · Freerdp

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the ClearCodec bands decode path when crafted band coordinates allow writes past the end of the destination surface buffer. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

7.7 CVSS 4.0 High EPSS 0.52% · top 58.1% CWE-122 · Heap-based buffer overflow
7.7CVSS 4.0 base score
0.52%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
13References, 1 tagged exploit
15 Jul 2026Last modified by NVD

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the ClearCodec bands decode path when crafted band coordinates allow writes past the end of the destination surface buffer. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L878-L879 Product
https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L883-L884 Product
https://github.com/FreeRDP/FreeRDP/releases/tag/3.21.0 Release Notes
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-3frr-mp8w-4599 ExploitVendor Advisory
https://access.redhat.com/errata/RHSA-2026:2048
https://access.redhat.com/errata/RHSA-2026:2081
https://access.redhat.com/errata/RHSA-2026:2222
https://access.redhat.com/errata/RHSA-2026:2736
https://access.redhat.com/errata/RHSA-2026:2952
https://access.redhat.com/errata/RHSA-2026:3037
https://access.redhat.com/security/cve/CVE-2026-23534
https://bugzilla.redhat.com/show_bug.cgi?id=2430888
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23534.json

Track CVE-2026-23534 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2026-31883Freerdp heap-based buffer overflow vulnerabilityFreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders lea…EPSS 0.32%9.8CVE-2024-32662Freerdp out-of-bounds read vulnerabilityFreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients prior to version 3.5.1 are vulnerable to out-of-bounds read. T…EPSS 0.77%9.8CVE-2024-32659Freerdp out-of-bounds read vulnerabilityFreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients prior to version 3.5.1 are vulnerable to out-of-bounds read if…EPSS 1.2%9.8CVE-2024-32658Freerdp out-of-bounds read vulnerabilityFreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients prior to version 3.5.1 are vulnerable to out-of-bounds read. V…EPSS 1.4%9.8CVE-2024-32459Freerdp out-of-bounds read vulnerabilityFreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients and servers that use a version of FreeRDP prior to 3.5.0 or 2.…EPSS 3.7%9.8CVE-2024-32460Freerdp out-of-bounds read vulnerabilityFreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based based clients using `/bpp:32` legacy `GDI` drawing path with a version…EPSS 1.9%9.8CVE-2024-32039Freerdp integer overflow vulnerabilityFreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients using a version of FreeRDP prior to 3.5.0 or 2.11.6 are vulner…EPSS 2.3%9.8CVE-2024-32040Freerdp vulnerabilityFreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients that use a version of FreeRDP prior to 3.5.0 or 2.11.6 and hav…EPSS 1.9%

Source: NIST National Vulnerability Database (record CVE-2026-23534), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.