Buffer overflow in Freerdp
CVE-2026-55827
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.1, FreeRDP clients launched with the non-default /cache:codec:rfx option pass desktop stride and height to RemoteFX decoding for Cache Bitmap V3 data while allocating bitmap->data only for the smaller DstWidth and DstHeight in gdi_Bitmap_Decompress, allowing a malicious RDP server to trigger a heap out-of-bounds write with attacker-controlled offset and content. This issue is fixed in version 3.27.1.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (43.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 43.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Freerdp — versions < 3.27.1
Weakness classification (CWE)
References
- github.com/FreeRDP/FreeRDP/security/advisories/GHSA-c495-h83v-3prp (Exploit, Mitigation, Vendor Advisory)
- github.com/FreeRDP/FreeRDP/pull/12899 (Patch)
- github.com/FreeRDP/FreeRDP/commit/e58adf922ea4c0d5495e59a1fe488d70092e0e3e (Patch)
- github.com/FreeRDP/FreeRDP/releases/tag/3.27.1 (Release Notes)
Frequently asked questions
- What is CVE-2026-55827?
- CVE-2026-55827 is a high-severity vulnerability in Freerdp, classified under Incorrect Calculation of Buffer Size. CVSS score: 7.5/10. Published 2026-07-10.
- How severe is CVE-2026-55827?
- High severity. CVSS v3 base score is 7.5 out of 10.