CVE-2026-23531

Summary

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 risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

Affected Software

VendorProductVersion RangeStatus
FreeRDPFreeRDP< 3.21.0affected

Weaknesses

  • CWE-122: CWE-122: Heap-based Buffer Overflow

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

freerdp: FreeRDP: Heap buffer overflow via crafted RDPGFX surface updates leads to denial of service and potential code execution.

Additional References

References