critical9.8
CVE-2026-23533
FreeRDP is a free implementation of the Remote Desktop Protocol.
Impact
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the RDPGFX ClearCodec decode path when maliciously crafted residual data causes out-of-bounds writes during color output. 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.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Freerdp | Freerdp | before 3.21.0 |
Weakness classification
References
- NVD record
- CVE.org record
- https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L268-L281
- https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L336
- https://github.com/FreeRDP/FreeRDP/releases/tag/3.21.0
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-32q9-m5qr-9j2v
- https://access.redhat.com/errata/RHSA-2026:2048
- https://access.redhat.com/errata/RHSA-2026:2081
- https://access.redhat.com/errata/RHSA-2026:2222
- https://access.redhat.com/errata/RHSA-2026:2714
- https://access.redhat.com/errata/RHSA-2026:2736
- https://access.redhat.com/errata/RHSA-2026:2770
- https://access.redhat.com/errata/RHSA-2026:2824
- https://access.redhat.com/errata/RHSA-2026:2952
- https://access.redhat.com/errata/RHSA-2026:3036
- https://access.redhat.com/errata/RHSA-2026:3037
- https://access.redhat.com/errata/RHSA-2026:3038
- https://access.redhat.com/errata/RHSA-2026:3039
- https://access.redhat.com/errata/RHSA-2026:3041
- https://access.redhat.com/security/cve/CVE-2026-23533
- https://bugzilla.redhat.com/show_bug.cgi?id=2430886
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23533.json