{"id":"CVE-2026-55564","summary":"FreeRDP: Out-of-bounds read in glyph_cache_get via crafted glyph fragments","details":"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-\u003enumber 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-\u003enumber 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.","aliases":["GHSA-6xmj-pr98-cx4c"],"modified":"2026-08-21T09:09:36.424945Z","published":"2026-08-19T17:45:47.438Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-125","CWE-193"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55564.json"},"references":[{"type":"WEB","url":"https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55564.json"},{"type":"ADVISORY","url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55564"},{"type":"FIX","url":"https://github.com/FreeRDP/FreeRDP/commit/c29324750e3cbcba8761f147b7a5235cc686930f"},{"type":"FIX","url":"https://github.com/FreeRDP/FreeRDP/pull/12885"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/freerdp/freerdp","events":[{"introduced":"0"},{"fixed":"c29324750e3cbcba8761f147b7a5235cc686930f"},{"fixed":"4f72b0979892352ff501e84d99832dc3bdc86a53"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"3.27.0"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["3.5.1","3.5.0","3.4.0","3.3.0","3.2.0","3.1.0","3.0.0","3.0.0-rc0","3.0.0-beta4","3.0.0-beta3","3.0.0-beta2","3.0.0-beta1","2.0.0","2.0.0-rc4","2.0.0-rc3","2.0.0-rc2","2.0.0-rc1","2.0.0-rc0","2.0.0-beta1+android11","2.0.0-beta1+android10","1.2.0-beta1+android9","1.2.0-beta1+android7","1.1.0-beta+2013071101","1.1.0-beta1+ios4","1.1.0-beta1+android5","1.1.0-beta1+android4","1.1.0-beta1+ios3","1.1.0-beta1+ios2","1.1.0-beta1+android3","1.1.0-beta1+android2","1.1.0-beta1+ios1","1.1.0-beta1","1.0.1","1.0.0","1.0-beta5","1.0-beta4","1.0-beta2","1.0-beta1"],"database_specific":{"vanir_signatures_modified":"2026-08-21T09:09:36Z","vanir_signatures":[{"signature_type":"Function","signature_version":"v1","source":"https://github.com/freerdp/freerdp/commit/c29324750e3cbcba8761f147b7a5235cc686930f","target":{"file":"libfreerdp/cache/glyph.c","function":"glyph_cache_get"},"deprecated":false,"digest":{"function_hash":"93036519385151388416460747969497365317","length":693},"id":"CVE-2026-55564-1f494f99"},{"deprecated":false,"digest":{"line_hashes":["52039373176474316678268215637408625998","141700248064839750362390075249856480766","9031375167578967402164386501519163610","48234736490559715598760602149096335597"],"threshold":0.9},"id":"CVE-2026-55564-6ce52ff7","signature_type":"Line","signature_version":"v1","source":"https://github.com/freerdp/freerdp/commit/c29324750e3cbcba8761f147b7a5235cc686930f","target":{"file":"libfreerdp/cache/glyph.c"}}],"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-55564.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L"}]}