CVE-2026-23531: FreeRDP is a free implementation of the Remote Desktop Protocol
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CRITICAL 9.8REMOTEUPGRADE
CVE-2026-23531 is a critical-severity flaw (CVSS 9.8) affecting freerdp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, in ClearCodec, when `glyphData` is present, `clear_decompress` calls `freerdp_image_copy_no_overlap` without validating the destination rectangle, allowing an out-of-bounds read/write via crafted RDPGFX surface updates. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution r
Verify at the official sourceNVD · CVE Program · Report a problem with this page Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-23531?
freerdp: upgrade to 3.21.0. Exact commands for each OS are on this page.
Is CVE-2026-23531 being exploited?
CVE-2026-23531 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-23531 affect?
CVE-2026-23531 affects freerdp. Severity is critical (CVSS 9.8). FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, in ClearCodec, when `glyphData` is present, `clear_decompress` calls `freerdp_image_copy_no_overlap` without validating the destination rectangle, all
How urgent is CVE-2026-23531?
Priority 56/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action