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.

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Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8561-1 FreeRDP vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 25 Aug 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Tue, 25 Aug 2026 04:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 19 Aug 2026 20:00:00 +0000

Type Values Removed Values Added
First Time appeared Freerdp
Freerdp freerdp
Vendors & Products Freerdp
Freerdp freerdp

Wed, 19 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
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.
Title FreeRDP: Out-of-bounds read in glyph_cache_get via crafted glyph fragments
Weaknesses CWE-125
CWE-193
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-25T03:33:53.901Z

Reserved: 2026-06-16T23:11:20.214Z

Link: CVE-2026-55564

cve-icon Vulnrichment

Updated: 2026-08-25T03:33:46.503Z

cve-icon NVD

Status : Received

Published: 2026-08-19T18:16:45.003

Modified: 2026-08-25T04:18:12.497

Link: CVE-2026-55564

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-19T17:45:47Z

Links: CVE-2026-55564 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-20T13:15:03Z

Weaknesses