CVE-2026-31897
Published: 13 March 2026
Summary
CVE-2026-31897 is a uncategorised-severity Out-of-bounds Read (CWE-125) vulnerability in Freerdp Freerdp. Its CVSS base score is 0.0.
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 15.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Threat & Defense at a Glance
Threat & Defense Details
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
OOB read in FreeRDP client bitmap handling is triggered by connecting to a malicious RDP server supplying malformed data; this directly matches the client-side exploitation vector in T1203 even though the reported impact is null.
NVD Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, there is an out-of-bounds read in freerdp_bitmap_decompress_planar when SrcSize is 0. The function dereferences *srcp (which points to pSrcData) without first verifying that SrcSize >= 1. When…
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SrcSize is 0 and pSrcData is non-NULL, this reads one byte past the end of the source buffer. This vulnerability is fixed in 3.24.0.
Deeper analysisAI
CVE-2026-31897 is an out-of-bounds read vulnerability (CWE-125) in the freerdp_bitmap_decompress_planar function of FreeRDP, a free implementation of the Remote Desktop Protocol. In versions prior to 3.24.0, the function dereferences a pointer to pSrcData without first checking if SrcSize is at least 1. When SrcSize is 0 and pSrcData is non-NULL, this results in reading one byte past the end of the source buffer.
The vulnerability has a CVSS v3.1 base score of 0.0 (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:N), indicating network accessibility, low attack complexity, no required privileges, but user interaction is necessary, with no impacts on confidentiality, integrity, or availability. An attacker can exploit it by tricking a user into processing malformed planar bitmap data via an RDP client connection, such as connecting to a malicious RDP server.
FreeRDP addresses this issue in version 3.24.0. Security practitioners should update to this version or later. Additional details are available in the GitHub security advisory at https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-xgv6-r22m-7c9x and the fixing commit at https://github.com/FreeRDP/FreeRDP/commit/cd27c8faca0eeb0d4309cc5837dfdf3c42eba4e7.
Details
- CWE(s)