CVE-2026-55564

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.

• CWE-125
• CWE-193

• https://github.com/FreeRDP/FreeRDP/commit/c29324750e3cbcba8761f147b7a5235cc686930fPatch
• https://github.com/FreeRDP/FreeRDP/pull/12885Issue Tracking, Patch
• https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0Release Notes
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4cExploit, Mitigation, Vendor Advisory
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4cExploit, Mitigation, Vendor Advisory

Published

Aug 19, 2026

Last Modified

Sep 22, 2026

Status

Analyzed

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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