CVE-2026-45700: Heap-buffer-overflow write in planar bitmap decoder

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 6.1% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-05-29 · updated 2026-07-29
Weakness: CWE-787

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, FreeRDP's planar bitmap decoder has an out-of-bounds heap write when decoding RLE planar data. In libfreerdp/codec/planar.c, freerdp_bitmap_decompress_planar() validates the X destination coordinate nXDst against the caller-provided destination stride (nDstStep) even when it is writing into the internal temp buffer pTempData. An attacker can bypass the check with a large nDstStep and a large nXDst, causing planar_decompress_plane_rle() to write past the end of pTempData. This vulnerability is fixed in 3.26.0.

Affected products

FreeRDP: before 3.26.0 — fixed in 3.26.0

How to fix

Upgrade to a fixed version: FreeRDP 3.26.0. Check the vendor advisory for mitigations.

References

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