← Vulnerability feed

Vulnerability record · CVE-2026-55564 · published 19 August 2026

CVE-2026-55564: Freerdp out-of-bounds read vulnerability

Freerdp · Freerdp

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, the glyph_cache_get function in libfreerdp/cache/glyph.c checks whether index is greater than cache->number instead of greater than or equal to it. A malicious RDP server can use GLYPH_FRAGMENT_USE replay in update_process_glyph_fragments to make the default cache receive index 254 when cache->number is 254, reading one pointer beyond the entries array and dereferencing it as a glyph. This can crash the client and may disclose adjacent heap data. This issue is fixed in version 3.27.0.

7.1 CVSS 3.1 High EPSS 0.44% · top 64.3% CWE-125 · Out-of-bounds readCWE-193 · CWE-193
7.1CVSS 3.1 base score
0.44%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
5References, 2 tagged exploit
22 Sep 2026Last modified by NVD

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, the glyph_cache_get function in libfreerdp/cache/glyph.c checks whether index is greater than cache->number instead of greater than or equal to it. A malicious RDP server can use GLYPH_FRAGMENT_USE replay in update_process_glyph_fragments to make the default cache receive index 254 when cache->number is 254, reading one pointer beyond the entries array and dereferencing it as a glyph. This can crash the client and may disclose adjacent heap data. This issue is fixed in version 3.27.0.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H

Affected products

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

References

LinkTags
https://github.com/FreeRDP/FreeRDP/commit/c29324750e3cbcba8761f147b7a5235cc686930f Patch
https://github.com/FreeRDP/FreeRDP/pull/12885 Issue TrackingPatch
https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0 Release Notes
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c ExploitMitigationVendor Advisory
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c ExploitMitigationVendor Advisory

Track CVE-2026-55564 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-2026-55564), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.