{"id":"CVE-2026-26955","summary":"FreeRDP has Out-of-bounds Write","details":"FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a malicious RDP server can trigger a heap buffer overflow in FreeRDP clients using the GDI surface pipeline (e.g., `xfreerdp`) by sending an RDPGFX ClearCodec surface command with an out-of-bounds destination rectangle. The `gdi_SurfaceCommand_ClearCodec()` handler does not call `is_within_surface()` to validate the command rectangle against the destination surface dimensions, allowing attacker-controlled `cmd-\u003eleft`/`cmd-\u003etop` (and subcodec rectangle offsets) to reach image copy routines that write into `surface-\u003edata` without bounds enforcement. The OOB write corrupts an adjacent `gdiGfxSurface` struct's `codecs*` pointer with attacker-controlled pixel data, and corruption of `codecs*` is sufficient to reach an indirect function pointer call (`NSC_CONTEXT.decode` at `nsc.c:500`) on a subsequent codec command — full instruction pointer (RIP) control demonstrated in exploitability harness. Users should upgrade to version 3.23.0 to receive a patch.","aliases":["GHSA-mr6w-ch7c-mqqj"],"modified":"2026-05-05T18:29:20.521540542Z","published":"2026-02-25T20:47:14.660Z","related":["ALSA-2026:5939","ALSA-2026:6004","ALSA-2026:6005","SUSE-SU-2026:1129-1","SUSE-SU-2026:1160-1","SUSE-SU-2026:1164-1","SUSE-SU-2026:1165-1","SUSE-SU-2026:1398-1","SUSE-SU-2026:21436-1","openSUSE-SU-2026:10408-1","openSUSE-SU-2026:10459-1","openSUSE-SU-2026:20632-1","openSUSE-SU-2026:20657-1"],"database_specific":{"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26955.json","cwe_ids":["CWE-787"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26955.json"},{"type":"ADVISORY","url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-mr6w-ch7c-mqqj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-26955"},{"type":"FIX","url":"https://github.com/FreeRDP/FreeRDP/commit/7d8fdce2d0ef337cb86cb37fc0c436c905e04d77"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/freerdp/freerdp","events":[{"introduced":"0"},{"fixed":"b933ae18d9ad2a1d73c610868fcc30eb61654070"}]}],"versions":["1.0-beta1","1.0-beta2","1.0-beta4","1.0-beta5","1.0.0","1.0.1","1.1.0-beta+2013071101","1.1.0-beta1","1.1.0-beta1+android2","1.1.0-beta1+android3","1.1.0-beta1+android4","1.1.0-beta1+android5","1.1.0-beta1+ios1","1.1.0-beta1+ios2","1.1.0-beta1+ios3","1.1.0-beta1+ios4","1.2.0-beta1+android7","1.2.0-beta1+android9","2.0.0","2.0.0-beta1+android10","2.0.0-beta1+android11","2.0.0-rc0","2.0.0-rc1","2.0.0-rc2","2.0.0-rc3","2.0.0-rc4","3.0.0","3.0.0-beta1","3.0.0-beta2","3.0.0-beta3","3.0.0-beta4","3.0.0-rc0","3.1.0","3.2.0","3.3.0","3.4.0","3.5.0","3.5.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-26955.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"}]}