--- id: CVE-2026-55194 title: FreeRDP is a free implementation of the Remote Desktop Protocol summary: >- FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, rpc_client_recv_fragment in libfreerdp/core/gateway/rpc_client.c ensures the response reassembly stream capacity using only the server-declared alloc_hint … severity: critical cvss: 9.8 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H' cwe: - CWE-122 - CWE-120 vendor: freerdp product: freerdp affected: - freerdp < 3.27.0 patched: - freerdp 3.27.0 published: '2026-08-19' updated: '2026-09-24' sourceUpdated: '2026-09-24T15:15:35.073' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55194' references: - url: >- https://github.com/FreeRDP/FreeRDP/commit/9f2da52c2341cc14a96ad12e69c5b83d0bcd8b5a label: security-advisories@github.com - url: 'https://github.com/FreeRDP/FreeRDP/pull/12873' label: security-advisories@github.com - url: 'https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0' label: security-advisories@github.com - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9gxm-3mf5-f5cx' label: security-advisories@github.com - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-55194.json - url: 'https://access.redhat.com/security/cve/CVE-2026-55194' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2519824' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-55194' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55194' - url: 'https://access.redhat.com/errata/RHSA-2026:68707' - url: 'https://access.redhat.com/errata/RHSA-2026:68706' - url: 'https://access.redhat.com/errata/RHSA-2026:61378' - url: 'https://access.redhat.com/errata/RHSA-2026:62571' - url: 'https://access.redhat.com/errata/RHSA-2026:65855' - url: 'https://access.redhat.com/errata/RHSA-2026:66281' - url: 'https://access.redhat.com/errata/RHSA-2026:66282' - url: 'https://access.redhat.com/errata/RHSA-2026:61379' - url: 'https://access.redhat.com/errata/RHSA-2026:71390' - url: 'https://access.redhat.com/errata/RHSA-2026:71388' - url: 'https://access.redhat.com/errata/RHSA-2026:71387' tags: - nvd - cve.org - exploit-available - csaf - vex - red-hat epss: 0.00619 epssPercentile: 0.47444 exploitAvailable: true ssvc: exploitation: poc automatable: 'no' technicalImpact: total timestamp: '2026-08-21T03:55:49.884406Z' scores: nvd: 9.8 cna: 8.7 vendor: 8.8 ingestedAt: '2026-09-13T18:54:55.030Z' --- ## Overview FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, rpc_client_recv_fragment in libfreerdp/core/gateway/rpc_client.c ensures the response reassembly stream capacity using only the server-declared alloc_hint rather than the actual StubLength about to be written. A malicious TS Gateway can send a PTYPE_RESPONSE with a small alloc_hint and a much larger frag_length, causing Stream_Write to copy attacker-controlled stub data beyond the 4096-byte pdu->s buffer. This can crash the client and may permit code execution through heap corruption. This issue is fixed in version 3.27.0. ## Affected - `freerdp < 3.27.0` ## Remediation Upgrade past the affected range: - `freerdp 3.27.0` ## Vendor advisories - **RHSA-2026:68707** · Red Hat · fixed in: Red Hat Enterprise Linux Server (v. 7 ELS), Red Hat Enterprise Linux Server Optional (v. 7 ELS) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68707) - **RHSA-2026:68706** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68706) - **RHSA-2026:61378** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-08-31 · [advisory](https://access.redhat.com/errata/RHSA-2026:61378) - **RHSA-2026:62571** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-09-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:62571) - **RHSA-2026:65855** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) · released 2026-09-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:65855) - **RHSA-2026:66281** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) · released 2026-09-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:66281) - **RHSA-2026:66282** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8) · released 2026-09-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:66282) - **RHSA-2026:61379** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) · released 2026-08-31 · [advisory](https://access.redhat.com/errata/RHSA-2026:61379) - **RHSA-2026:71390** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-09-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:71390) - **RHSA-2026:71388** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-09-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:71388) - **RHSA-2026:71387** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat CodeReady Linux Builder EUS (v.9.6) · released 2026-09-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:71387)