FreeRDP versions 3.28.0 and earlier contain an out-of-bounds read vulnerability in the RDP6 planar RLE bitmap decoder functions… (CVE-2026-67306)
FreeRDP versions 3.28.0 and earlier contain an out-of-bounds read vulnerability in the RDP6 planar RLE bitmap decoder functions planar_decompress_plane_rle and planar_decompress_plane_rle_only in libfreerdp/codec/planar.c. Only the 1-byte control byte is bounds-checked; the subsequent 0–15 attacker-declared raw bytes are read without validating that the source buffer contains them. A malicious or compromised RDP server can send a truncated planar-encoded bitmap or surface update (reachable via both the Bitmap Update PDU and RDPGFX Surface Command paths) that causes the client to read past the end of the source buffer. The issue is fixed in FreeRDP 3.29.0.
AI Analysis
Technical Summary
An out-of-bounds read vulnerability (CWE-125) exists in FreeRDP versions 3.28.0 and earlier within the RDP6 planar RLE bitmap decoder functions planar_decompress_plane_rle and planar_decompress_plane_rle_only. The vulnerability occurs because only the 1-byte control byte is bounds-checked, but the following 0 to 15 raw bytes declared by an attacker are read without validating the source buffer length. This can be triggered by a malicious or compromised RDP server sending a truncated planar-encoded bitmap or surface update via Bitmap Update PDU or RDPGFX Surface Command, leading to out-of-bounds memory reads on the client side. The issue is resolved in FreeRDP 3.29.0.
Potential Impact
The vulnerability allows an attacker controlling or compromising an RDP server to cause the FreeRDP client to perform out-of-bounds reads, potentially leading to information disclosure or client instability. The CVSS score of 5.4 (medium severity) reflects limited confidentiality impact, no integrity impact, and low availability impact. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade FreeRDP to version 3.29.0 or later, where this vulnerability is fixed. No other mitigations are indicated. Patch status is confirmed fixed in 3.29.0.
FreeRDP versions 3.28.0 and earlier contain an out-of-bounds read vulnerability in the RDP6 planar RLE bitmap decoder functions… (CVE-2026-67306)
Description
FreeRDP versions 3.28.0 and earlier contain an out-of-bounds read vulnerability in the RDP6 planar RLE bitmap decoder functions planar_decompress_plane_rle and planar_decompress_plane_rle_only in libfreerdp/codec/planar.c. Only the 1-byte control byte is bounds-checked; the subsequent 0–15 attacker-declared raw bytes are read without validating that the source buffer contains them. A malicious or compromised RDP server can send a truncated planar-encoded bitmap or surface update (reachable via both the Bitmap Update PDU and RDPGFX Surface Command paths) that causes the client to read past the end of the source buffer. The issue is fixed in FreeRDP 3.29.0.
CVSS v3.1
Score 5.4medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
An out-of-bounds read vulnerability (CWE-125) exists in FreeRDP versions 3.28.0 and earlier within the RDP6 planar RLE bitmap decoder functions planar_decompress_plane_rle and planar_decompress_plane_rle_only. The vulnerability occurs because only the 1-byte control byte is bounds-checked, but the following 0 to 15 raw bytes declared by an attacker are read without validating the source buffer length. This can be triggered by a malicious or compromised RDP server sending a truncated planar-encoded bitmap or surface update via Bitmap Update PDU or RDPGFX Surface Command, leading to out-of-bounds memory reads on the client side. The issue is resolved in FreeRDP 3.29.0.
Potential Impact
The vulnerability allows an attacker controlling or compromising an RDP server to cause the FreeRDP client to perform out-of-bounds reads, potentially leading to information disclosure or client instability. The CVSS score of 5.4 (medium severity) reflects limited confidentiality impact, no integrity impact, and low availability impact. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade FreeRDP to version 3.29.0 or later, where this vulnerability is fixed. No other mitigations are indicated. Patch status is confirmed fixed in 3.29.0.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-3j62-96cj-jq88
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-67306"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6a6e6298bf32cb7a344f9d19
Added to database: 08/01/2026, 21:18:16 UTC
Last enriched: 08/01/2026, 21:24:09 UTC
Last updated: 09/16/2026, 22:01:37 UTC
Views: 46
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