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CVE-2026-55191

critical

FreeRDP is a free implementation of the Remote Desktop Protocol.

Vendor / product: Freerdp — freerdp

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP clients that negotiate RDPGFX AVC444 with an H.264 decoder backend calculate the intermediate YUV444 allocation size in libfreerdp/codec/h264.c with 32-bit multiplication in avc444_ensure_buffer. A malicious RDP server can supply surface dimensions for which piDstStride multiplied by padDstHeight wraps to a small nonzero value, causing winpr_aligned_recalloc to allocate an undersized buffer before YUV420CombineToYUV444 writes using the actual stride and rectangle dimensions. This can cause a client crash and may permit code execution through attacker-influenced heap corruption. This issue is fixed in version 3.27.0.

CVSS
9.8
9.8 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity source: NVD CVSS v3.1 (nvd@nist.gov)
Timeline (UTC)
Published: 2026-08-19 18:16
Modified: 2026-10-26 11:10
NVD status: Analyzed
Last synced 2 days ago
Verified against the source API 2026-10-27 07:07 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

freerdp / freerdp <3.27.0

Weakness classification (CWE)

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr
Vendor advisory: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr
Patch / mitigation: https://github.com/FreeRDP/FreeRDP/commit/97f40b9e766af375f4e41ac6a3f4397d708d249c
Patch / mitigation: https://github.com/FreeRDP/FreeRDP/pull/12873
Patch / mitigation: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr
Patch / mitigation: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr

References

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 07:07 UTC · record ↗

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