{"id":"CVE-2026-63633","title":"FreeRDP is a free implementation of the Remote Desktop Protocol","summary":"FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, freerdp_dsp_decode_opus in libfreerdp/codec/dsp.c calls Stream_EnsureRemainingCapacity on context->common.buffer even though opus_decode writes decoded PCM…","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 < 3.28.0"],"patched":["freerdp 3.28.0"],"published":"2026-08-19","updated":"2026-09-24","sourceUpdated":"2026-09-24T15:10:37.590","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63633","references":[{"url":"https://github.com/FreeRDP/FreeRDP/commit/0ed1f95d36913581cf31124f94eb5843d4263eae","label":"security-advisories@github.com"},{"url":"https://github.com/FreeRDP/FreeRDP/pull/12993","label":"security-advisories@github.com"},{"url":"https://github.com/FreeRDP/FreeRDP/releases/tag/3.28.0","label":"security-advisories@github.com"},{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-72j9-356v-88xq","label":"security-advisories@github.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63633.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-63633"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2519826"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63633"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63633"},{"url":"https://access.redhat.com/errata/RHSA-2026:61378"},{"url":"https://access.redhat.com/errata/RHSA-2026:68706"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00619,"epssPercentile":0.49454,"scores":{"nvd":9.8,"vendor":8.8},"ingestedAt":"2026-09-09T21:22:45.541Z","slug":"CVE-2026-63633","body":"## Overview\n\nFreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, freerdp_dsp_decode_opus in libfreerdp/codec/dsp.c calls Stream_EnsureRemainingCapacity on context->common.buffer even though opus_decode writes decoded PCM into the caller-supplied out stream. A malicious RDP server that negotiates WAVE_FORMAT_OPUS with a client built with WITH_OPUS enabled and WITH_DSP_FFMPEG disabled can make libopus write a large decoded frame beyond the 4096-byte StreamPool_Take destination used by channels/rdpsnd/client/rdpsnd_main.c. This can corrupt the client heap, crash the client, and may permit code execution. This issue is fixed in version 3.28.0.\n\n## Affected\n\n- `freerdp < 3.28.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `freerdp 3.28.0`\n\n## Vendor advisories\n\n- **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)\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 9 · updated 2026-09-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63633.json)\n- **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)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":210180,"id":"CVE-2026-63633","ts":1790264791909,"field":"cvss","old":"8.8","new":"9.8"},{"seq":210179,"id":"CVE-2026-63633","ts":1790264791909,"field":"severity","old":"high","new":"critical"},{"seq":206378,"id":"CVE-2026-63633","ts":1789663223721,"field":"cvss","old":null,"new":"8.8"},{"seq":206377,"id":"CVE-2026-63633","ts":1789663223721,"field":"severity","old":"none","new":"high"}]}