Reference page — cumulative record through Saturday, October 3, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-55564

CVE-2026-55564HIGH

FreeRDP: Out-of-bounds read in glyph_cache_get via crafted glyph fragments

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   R  U  L  N  H    7.1   .0044   35.9     —

AFFECTED
  Product  Versions    Fixed
  FreeRDP  < 3.27.0 –  —

TIMELINE
  Jun 16  Reserved by GitHub_M
  Aug 19  Published (CNA: GitHub_M)
  Sep 22  EXPLOIT PUBLISHED — CVE-2026-55564 (FreeRDP). Public exploit reference added.
  Sep 22  RESCORED — CVE-2026-55564 (FreeRDP). CVSS 5.4 → 7.1 (NVD).

CWE-125, CWE-193 · CNA: GitHub_M · CVSS v3.1 · 4 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
June 16, 2026	Reserved	Reserved by GitHub_M
August 19, 2026	Published	Published (CNA: GitHub_M)
September 22, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-55564 (FreeRDP). Public exploit reference added.
September 22, 2026	RESCORED	RESCORED — CVE-2026-55564 (FreeRDP). CVSS 5.4 → 7.1 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
FreeRDP	FreeRDP	—	< 3.27.0	—

Weaknesses

CWE-125 · CWE-193

References (4)

https://github.com/FreeRDP/FreeRDP/commit/c29324750e3cbcba8761f147b7a5235cc686930f [Patch]
https://github.com/FreeRDP/FreeRDP/pull/12885 [Issue Tracking, Patch]
https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0 [Release Notes]
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c [Exploit, Mitigation, Vendor Advisory]

Authoritative record: CVE-2026-55564 at cve.org

Vendors: freerdp

Weaknesses: CWE-125 · CWE-193

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-55564 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Saturday, October 3, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.