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High ALAS2-2026-3356 4 CVEs

Important: freerdp security update (Amazon Linux 2)

Published Jun 11, 2026 · Updated Jun 22, 2026

Summary

Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2026-45700: 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. CVE-2026-44421: FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client by sending crafted RDPGFX PDUs. The bug is in gdi_CacheToSurface: it validates a destination rectangle that is clamped to UINT16_MAX, but then performs the copy using the original cacheEntry->width/height. This can cause a large out-of-bounds heap write and may lead to client crashes or code execution. This bug is reachable from a malicious RDP server, but only when the client has RDPGFX enabled. This vulnerability is fixed in 3.26.0. CVE-2026-44420: FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP client can trigger a heap-buffer-overflow write in FreeRDP's server-side clipboard (cliprdr) channel by sending a CB_CLIP_CAPS PDU with a too-small capabilitySetLength. This can crash the server process (remote DoS) and may be exploitable for code execution because it corrupts heap memory. This vulnerability is fixed in 3.26.0. CVE-2026-40033: FreeRDP before 3.26.0 contains a heap-buffer-overflow vulnerability in gdi_CacheToSurface that allows remote attackers to write out-of-bounds heap memory. The vulnerability occurs because rectangle validation clamps coordinates to UINT16_MAX but performs copy operations using unclamped cache entry dimensions, enabling malicious RDP servers to trigger large out-of-bounds writes and potentially achieve remote code execution or client crash.

Fixed packages 6

ReleasePackageFixed in
Amazon Linux · 2 freerdp 2:2.11.7-1.amzn2.0.12
Amazon Linux · 2 freerdp-debuginfo 2:2.11.7-1.amzn2.0.12
Amazon Linux · 2 freerdp-devel 2:2.11.7-1.amzn2.0.12
Amazon Linux · 2 freerdp-libs 2:2.11.7-1.amzn2.0.12
Amazon Linux · 2 libwinpr 2:2.11.7-1.amzn2.0.12
Amazon Linux · 2 libwinpr-devel 2:2.11.7-1.amzn2.0.12

Vulnerabilities 4

  • High 8.8

    FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass

    FreeRDP before 3.26.0 contains a heap-buffer-overflow vulnerability in gdi_CacheToSurface that allows remote attackers to write out-of-bounds heap memory. The vulnerability occurs because rectangle validation clamps coordinates to UINT16_MAX but performs copy…

  • High 8.8

    FreeRDP cliprdr server heap-buffer-overflow via undersized capabilitySetLength in CB_CLIP_CAPS

    FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP client can trigger a heap-buffer-overflow write in FreeRDP's server-side clipboard (cliprdr) channel by sending a CB_CLIP_CAPS PDU with a too-small capabilitySet…

  • High 8.8

    FreeRDP RDPGFX CacheToSurface heap-buffer-overflow via clamped-rectangle validation bypass

    FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client by sending crafted RDPGFX PDUs. The bug is in gdi_CacheToSurface: it validates a destinatio…

  • High 7.7

    Heap-buffer-overflow write in planar bitmap decoder

    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 d…

References

  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-40033.html
  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-44420.html
  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-44421.html
  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-45700.html