CVE-2026-22858
published 2026-01-14CVE-2026-22858: 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…
PriorityP359critical9.1CVSS 3.1
AVNACLPRNUINSUCHINAH
EPSS
0.60%
44.7th percentile
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
5 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | freerdp2 | < freerdp3 3.20.2+dfsg-1 (forky) | freerdp3 3.20.2+dfsg-1 (forky) |
| debian | freerdp3 | < freerdp3 3.20.2+dfsg-1 (forky) | freerdp3 3.20.2+dfsg-1 (forky) |
| freerdp | freerdp | < 3.20.1 | 3.20.1 |
| ubuntu | freerdp2 | — | — |
| ubuntu | freerdp3 | — | — |
CVSS provenance
nvdv3.19.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
nvdv4.05.6MEDIUMCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
osv5.6MEDIUM
vendor_ubuntu9.1CRITICAL
vendor_debian5.6MEDIUM
vendor_redhat5.6MEDIUM
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VulDB
FreeRDP up to 3.20.0 out-of-bounds (GHSA-qmqf-m84q-x896 / EUVD-2026-2669)
vuldb·2026-06-11·CVSS 9.1
CVE-2026-22858 [CRITICAL] FreeRDP up to 3.20.0 out-of-bounds (GHSA-qmqf-m84q-x896 / EUVD-2026-2669)
A vulnerability was found in FreeRDP up to 3.20.0. It has been rated as problematic. Affected is an unknown function. This manipulation causes out-of-bounds read.
This vulnerability is handled as CVE-2026-22858. The attack can be initiated remotely. There is not any exploit available.
Upgrading the affected component is advised.
OSV
CVE-2026-22858: FreeRDP is a free implementation of the Remote Desktop Protocol
osv·2026-01-14·CVSS 5.6
CVE-2026-22858 [MEDIUM] CVE-2026-22858: FreeRDP is a free implementation of the Remote Desktop Protocol
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.
Ubuntu
FreeRDP vulnerabilities
vendor_ubuntu·2026-06-16·CVSS 9.1
CVE-2026-45700 [CRITICAL] FreeRDP vulnerabilities
Title: FreeRDP vulnerabilities
Summary: Several security issues were fixed in FreeRDP.
It was discovered that FreeRDP incorrectly handled memory under certain
circumstances, which could lead to an out-of-bounds heap write. An
attacker could possibly use this issue to cause a denial of service or
execute arbitrary code. (CVE-2026-45700)
In addition, this update fixes a regression introduced in USN-8105-1.
The update introduces a complete fix for CVE-2026-22858, CVE-2026-23732
and CVE-2026-25952 in Ubuntu 24.04 LTS and Ubuntu 25.10.
Instructions: In general, a standard system update will make all the necessary changes.
Ubuntu
FreeRDP vulnerabilities
vendor_ubuntu·2026-03-18
CVE-2026-25954 FreeRDP vulnerabilities
Title: FreeRDP vulnerabilities
Summary: Several security issues were fixed in FreeRDP.
It was discovered that FreeRDP incorrectly handled certain RDP packets. A
remote attacker could use this issue to cause FreeRDP to crash, resulting
in a denial of service, or possibly execute arbitrary code.
Instructions: In general, a standard system update will make all the necessary changes.
Red Hat
freerdp: FreeRDP global-buffer-overflow
vendor_redhat·2026-01-14·CVSS 5.6
CVE-2026-22858 [MEDIUM] CWE-787 freerdp: FreeRDP global-buffer-overflow
freerdp: FreeRDP global-buffer-overflow
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.
A global buffer overflow flaw has been discovered in FreeRDP. This global-buffer-overflow was observed in FreeRDP's Base64 decoding path. The root cause appears to be implementation-defined char signedne
Debian
CVE-2026-22858: freerdp2 - FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1...
vendor_debian·2026·CVSS 5.6
CVE-2026-22858 [MEDIUM] CVE-2026-22858: freerdp2 - FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1...
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.
Scope: local
bookworm: open
bullseye: open
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-22858 freerdp: FreeRDP global-buffer-overflow
bugzilla·2026-01-14·CVSS 5.6
CVE-2026-22858 [MEDIUM] CVE-2026-22858 freerdp: FreeRDP global-buffer-overflow
CVE-2026-22858 freerdp: FreeRDP global-buffer-overflow
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.
Discussion:
This issue has been addressed in the following products:
Red Hat Enterprise Linux 10
Via RHSA-2026:3068 https://access.redhat.com/errata/RHSA-2026:3068
---
This issue has
Bugzilla
CVE-2026-22858 freerdp2: FreeRDP global-buffer-overflow [fedora-42]
bugzilla·2026-01-14·CVSS 5.6
CVE-2026-22858 [MEDIUM] CVE-2026-22858 freerdp2: FreeRDP global-buffer-overflow [fedora-42]
CVE-2026-22858 freerdp2: FreeRDP global-buffer-overflow [fedora-42]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Discussion:
This message is a reminder that Fedora Linux 42 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora Linux 42 on 2026-05-13.
It is Fedora's policy to close all bug reports from releases that are no longer
maintained. At that time this bug will be closed as EOL if it remains open with a
'version' of '42'.
Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, change the 'version'
to a lat
Wiz
CVE-2026-22858 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 5.6
CVE-2026-22858 [MEDIUM] CVE-2026-22858 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-22858 :
NixOS vulnerability analysis and mitigation
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.
Source : NVD
## 5.6
Score
Published January 14, 2026
Severity MEDIUM
CNA Score 5.6
Affected Technologies
NixOS
Rocky Linux
Has Public Exploit Yes
Has CISA KEV Exploit
https://github.com/FreeRDP/FreeRDP/releases/tag/3.20.1https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qmqf-m84q-x896https://access.redhat.com/errata/RHSA-2026:19033https://access.redhat.com/errata/RHSA-2026:3067https://access.redhat.com/errata/RHSA-2026:3068https://access.redhat.com/errata/RHSA-2026:3334https://access.redhat.com/errata/RHSA-2026:3975https://access.redhat.com/errata/RHSA-2026:4121https://access.redhat.com/errata/RHSA-2026:4433https://access.redhat.com/errata/RHSA-2026:4437https://access.redhat.com/errata/RHSA-2026:4438https://access.redhat.com/errata/RHSA-2026:4439https://access.redhat.com/errata/RHSA-2026:4440https://access.redhat.com/errata/RHSA-2026:4446https://access.redhat.com/errata/RHSA-2026:4471https://access.redhat.com/errata/RHSA-2026:4489https://access.redhat.com/security/cve/CVE-2026-22858https://bugzilla.redhat.com/show_bug.cgi?id=2429649https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-22858.json
2026-01-14
Published