{"id":"DEBIAN-CVE-2026-26955","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.","modified":"2026-09-01T16:06:36.524916416Z","published":"2026-02-25T21:16:42.863Z","upstream":["CVE-2026-26955"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-26955"}],"affected":[{"package":{"name":"freerdp2","ecosystem":"Debian:12","purl":"pkg:deb/debian/freerdp2?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.0+dfsg1-1","2.10.0+dfsg1-1.1","2.11.2+dfsg1-1","2.11.2+dfsg1-1.1~exp1","2.11.2+dfsg1-1.1~exp2","2.11.5+dfsg1-1","2.11.7+dfsg1-1","2.11.7+dfsg1-2","2.11.7+dfsg1-3","2.11.7+dfsg1-4","2.11.7+dfsg1-5","2.11.7+dfsg1-6","2.11.7+dfsg1-6~deb12u1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-26955.json"}},{"package":{"name":"freerdp3","ecosystem":"Debian:13","purl":"pkg:deb/debian/freerdp3?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.15.0+dfsg-2.1+deb13u1"}]}],"versions":["3.15.0+dfsg-2.1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-26955.json"}},{"package":{"name":"freerdp3","ecosystem":"Debian:14","purl":"pkg:deb/debian/freerdp3?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.23.0+dfsg-1"}]}],"versions":["3.15.0+dfsg-2.1","3.16.0+dfsg-1","3.16.0+dfsg-2","3.17.0+dfsg-1","3.17.1+dfsg-1","3.17.1+dfsg-2","3.17.2+dfsg-1","3.17.2+dfsg-2","3.17.2+dfsg-3","3.18.0+dfsg-1","3.19.0+dfsg-1","3.19.1+dfsg-1","3.20.0+dfsg-1","3.20.2+dfsg-1","3.21.0+dfsg-1","3.22.0+dfsg-1","3.22.0+dfsg-1~bpo13+0","3.22.0+dfsg-1~bpo13+1","3.22.0+dfsg-3","3.23.0+dfsg-1~bpo13+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-26955.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"}]}