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Vulnerability · Published Jan 14, 2026 · Assigned by GitHub_M

CVE-2026-22858FreeRDP has a global-buffer-overflow in crypto_base64_decode

High 7.4

In plain English

A high-severity out-of-bounds read in FreeRDP from FreeRDP. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.4High
Exploit odds (30 days)0.7%top 46.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10freerdp2:3.10.3-5.el10_1.2ALSA-2026:3068
AlmaLinux:8freerdp2:2.11.7-3.el8_10ALSA-2026:3334
AlmaLinux:9freerdp2:2.11.7-1.el9_7.2ALSA-2026:3067
AlmaLinux:10freerdp-devel2:3.10.3-5.el10_1.2ALSA-2026:3068
AlmaLinux:8freerdp-devel2:2.11.7-3.el8_10ALSA-2026:3334
AlmaLinux:9freerdp-devel2:2.11.7-1.el9_7.2ALSA-2026:3067
AlmaLinux:10freerdp-libs2:3.10.3-5.el10_1.2ALSA-2026:3068
AlmaLinux:8freerdp-libs2:2.11.7-3.el8_10ALSA-2026:3334
AlmaLinux:9freerdp-libs2:2.11.7-1.el9_7.2ALSA-2026:3067
AlmaLinux:10freerdp-server2:3.10.3-5.el10_1.2ALSA-2026:3068
AlmaLinux:10libwinpr2:3.10.3-5.el10_1.2ALSA-2026:3068
AlmaLinux:8libwinpr2:2.11.7-3.el8_10ALSA-2026:3334
AlmaLinux:9libwinpr2:2.11.7-1.el9_7.2ALSA-2026:3067
AlmaLinux:10libwinpr-devel2:3.10.3-5.el10_1.2ALSA-2026:3068
AlmaLinux:8libwinpr-devel2:2.11.7-3.el8_10ALSA-2026:3334
AlmaLinux:9libwinpr-devel2:2.11.7-1.el9_7.2ALSA-2026:3067
Alpine:v3.23freerdp3.22.0-r0ALPINE-CVE-2026-22858
Debian:12freerdp2no fix listedDEBIAN-CVE-2026-22858
Debian:13freerdp33.15.0+dfsg-2.1+deb13u1DEBIAN-CVE-2026-22858
Debian:14freerdp33.20.2+dfsg-1DEBIAN-CVE-2026-22858
Rocky Linux:10freerdp2:3.10.3-5.el10_1.2RLSA-2026:3068
Rocky Linux:8freerdp2:2.11.7-3.el8_10RLSA-2026:3334
Rocky Linux:9freerdp2:2.11.7-1.el9_7.2RLSA-2026:3067
Ubuntu:22.04:LTSfreerdp2no fix listedUBUNTU-CVE-2026-22858
Ubuntu:24.04:LTSfreerdp33.5.1+dfsg1-0ubuntu1.4USN-8105-1
Ubuntu:24.04:LTSfreerdp33.5.1+dfsg1-0ubuntu1.4UBUNTU-CVE-2026-22858
Ubuntu:25.10freerdp33.16.0+dfsg-2ubuntu0.3USN-8105-1
Ubuntu:25.10freerdp33.16.0+dfsg-2ubuntu0.3UBUNTU-CVE-2026-22858
Ubuntu:26.04:LTSfreerdp33.20.2+dfsg-1UBUNTU-CVE-2026-22858

Affected products (as reported)

VendorProductVersions
FreeRDP FreeRDP < 3.20.1

Weakness: CWE-125, CWE-758, CWE-787 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

References