CVE-2026-22858CRITICAL 9.1EPSS p30.0%
CVE-2026-22858CVE-2026-22858
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, global-buffer-overflow was observed in FreeRDP's Base64 decoding path. The root cause appears to be implementation-defined char signedness: on Arm/AArch64 builds, plain char is treated as unsigned, so the guard c <= 0 can be optimized into a simple c != 0 check. As a result, non-ASCII bytes (e.g., 0x80-0xFF) may bypass the intended range restriction and be used as an index into a global lookup table, causing out-of-bounds access. This vulnerability is fixed in 3.20.1.
Scoring
| CVSS 3.1 | 9.1 (CRITICAL) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
| EPSS | 0.38% probability of exploitation · percentile 30.0% · 2026-06-18T12:00:27Z |
| Published | 2026-01-14 |
| Last modified | 2026-01-20 |
Underlying weaknesses· 2
References
2
| Type | Target | Confidence | Tier |
|---|---|---|---|
| Weakness | Out-of-bounds Readcwe-125 | 0% | live |
| Weakness | Reliance on Undefined, Unspecified, or Implementation-Defined Behaviorcwe-758 | 0% | live |
Related by meaning· 6
Nearest entities by semantic similarity across the cs-graph corpus.