{"id":"CVE-2026-55564","state":"PUBLISHED","title":"FreeRDP: Out-of-bounds read in glyph_cache_get via crafted glyph fragments","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.","publishedAt":"2026-08-19T17:45:47.438Z","updatedAt":"2026-08-25T03:33:53.901Z","severity":{"score":5.4,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["FreeRDP FreeRDP"],"affected":[{"vendor":"FreeRDP","product":"FreeRDP","versions":[{"version":"< 3.27.0","status":"affected"}]}],"references":["https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c","https://github.com/FreeRDP/FreeRDP/pull/12885","https://github.com/FreeRDP/FreeRDP/commit/c29324750e3cbcba8761f147b7a5235cc686930f","https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0"],"weaknesses":["CWE-125","CWE-193"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55564.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55564","state":"PUBLISHED","datePublished":"2026-08-19T17:45:47.438Z","dateUpdated":"2026-08-25T03:33:53.901Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T23:11:20.214Z"},"containers":{"cna":{"title":"FreeRDP: Out-of-bounds read in glyph_cache_get via crafted glyph fragments","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"FreeRDP","product":"FreeRDP","versions":[{"version":"< 3.27.0","status":"affected"}]}],"references":[{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c","name":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/FreeRDP/FreeRDP/pull/12885","name":"https://github.com/FreeRDP/FreeRDP/pull/12885","tags":["x_refsource_MISC"]},{"url":"https://github.com/FreeRDP/FreeRDP/commit/c29324750e3cbcba8761f147b7a5235cc686930f","name":"https://github.com/FreeRDP/FreeRDP/commit/c29324750e3cbcba8761f147b7a5235cc686930f","tags":["x_refsource_MISC"]},{"url":"https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0","name":"https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":5.4,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","description":"CWE-125: Out-of-bounds Read","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-193","lang":"en","description":"CWE-193: Off-by-one Error","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-19T17:45:47.438Z"},"source":{"advisory":"GHSA-6xmj-pr98-cx4c","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-25T03:33:25.244841Z","id":"CVE-2026-55564","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-25T03:33:53.901Z"}}]}}}