CVE-2026-23531

Description

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.

References

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23531.json

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-xj5h-9cr5-23c5

https://github.com/FreeRDP/FreeRDP/releases/tag/3.21.0

https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L1139-L1145

https://bugzilla.redhat.com/show_bug.cgi?id=2430887

https://access.redhat.com/security/cve/CVE-2026-23531

https://access.redhat.com/errata/RHSA-2026:3041

https://access.redhat.com/errata/RHSA-2026:3039

https://access.redhat.com/errata/RHSA-2026:3038

https://access.redhat.com/errata/RHSA-2026:3037

https://access.redhat.com/errata/RHSA-2026:3036

https://access.redhat.com/errata/RHSA-2026:2952

https://access.redhat.com/errata/RHSA-2026:2824

https://access.redhat.com/errata/RHSA-2026:2770

https://access.redhat.com/errata/RHSA-2026:2736

https://access.redhat.com/errata/RHSA-2026:2714

https://access.redhat.com/errata/RHSA-2026:2222

https://access.redhat.com/errata/RHSA-2026:2081

https://access.redhat.com/errata/RHSA-2026:2048

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4

EPSS