U.S. flag   An official website of the United States government
Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock (Dot gov) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-55564 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to [email protected].

URL Source(s) Tag(s)
https://github.com/FreeRDP/FreeRDP/commit/c29324750e3cbcba8761f147b7a5235cc686930f GitHub, Inc.
https://github.com/FreeRDP/FreeRDP/pull/12885 GitHub, Inc.
https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0 GitHub, Inc.
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-125 Out-of-bounds Read GitHub, Inc.  
CWE-193 Off-by-one Error GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-55564
NVD Published Date:
08/19/2026
NVD Last Modified:
08/19/2026
Source:
GitHub, Inc.