CVE-2026-22858: FreeRDP is a free implementation of the Remote Desktop Protocol

Q: How do I fix CVE-2026-22858?

freerdp: upgrade to 3.20.1. Exact commands for each OS are on this page.

Q: Is CVE-2026-22858 being exploited?

CVE-2026-22858 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-22858 affect?

CVE-2026-22858 affects freerdp. Severity is critical (CVSS 9.1). 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 bui

Q: How urgent is CVE-2026-22858?

Priority 55/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

CRITICAL 9.1REMOTEUPGRADE

CVE-2026-22858 is a critical-severity flaw (CVSS 9.1) affecting freerdp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 a

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Weakness	CWE-125, CWE-758, CWE-787
Published	2026-01-14
Last modified	2026-07-15

Publisher (CNA): GitHub, Inc. · Vendor: freerdp

Last updated 2026-07-15 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-01-14 18:16 UTCPublished CVE record published
2026-07-15 02:18 UTCUpdated Record last modified

freerdp freerdp UPGRADE

Affected: < 3.20.1

Fixed in: 3.20.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy freerdp || rpm -q freerdp || freerdp --version

2. UPGRADE to 3.20.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade freerdp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade freerdp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Fedora ELN · openldap · FIXED · 2.6.16-1.eln159 · FEDORA-2026-4b30c86326 · source

sudo dnf upgrade --advisory=FEDORA-2026-4b30c86326

Fedora 46 · php-pecl-yac · FIXED · 3.0.1-2.fc46 · FEDORA-2026-5f43289aa2 · source

sudo dnf upgrade --advisory=FEDORA-2026-5f43289aa2

Ubuntu 24.04 · freerdp3 · FIXED · 3.5.1+dfsg1-0ubuntu1.4

sudo apt update && sudo apt install --only-upgrade freerdp3 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' freerdp3)" ge "3.5.1+dfsg1-0ubuntu1.4" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 25.10 · freerdp3 · FIXED · 3.16.0+dfsg-2ubuntu0.3

sudo apt update && sudo apt install --only-upgrade freerdp3 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' freerdp3)" ge "3.16.0+dfsg-2ubuntu0.3" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · freerdp2 · NO FIX YET

Debian 13 · freerdp3 · FIXED · 3.15.0+dfsg-2.1+deb13u1

sudo apt update && sudo apt install --only-upgrade freerdp3 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' freerdp3)" ge "3.15.0+dfsg-2.1+deb13u1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 10 · freerdp · FIXED · freerdp-3.10.3-5.el10_1.2

sudo dnf upgrade --advisory=RHSA-2026:3068 rpm -q freerdp

RHEL 10.0 Extended Update Support · freerdp · FIXED · freerdp-3.10.3-3.el10_0.2

sudo dnf upgrade --advisory=RHSA-2026:4121 rpm -q freerdp

RHEL 7 Extended Lifecycle Support · freerdp · FIXED · freerdp-2.1.1-5.el7_9.2

sudo dnf upgrade --advisory=RHSA-2026:4471 rpm -q freerdp

RHEL 8 · freerdp · FIXED · freerdp-2.11.7-3.el8_10

sudo dnf upgrade --advisory=RHSA-2026:3334 rpm -q freerdp

RHEL 8.2 Advanced Update Support · freerdp · FIXED · freerdp-2.0.0-46.rc4.el8_2.7

sudo dnf upgrade --advisory=RHSA-2026:4433 rpm -q freerdp

Alpine 3.23 · freerdp · FIXED · freerdp-3.22.0-r0

apk add --upgrade freerdp apk info -v freerdp

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2026-1433 · source

sudo dnf update --advisory=ALAS2023-2026-1433

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qmqf-m84q-x896

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-22858?

freerdp: upgrade to 3.20.1. Exact commands for each OS are on this page.

Is CVE-2026-22858 being exploited?

CVE-2026-22858 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-22858 affect?

CVE-2026-22858 affects freerdp. Severity is critical (CVSS 9.1). 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 bui

How urgent is CVE-2026-22858?

Priority 55/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

WinRM and RDP vulnerabilities

Related CVEs

CVE-2026-111379 HIGH 7.3 UPGRADE FreeRDP before 3.32.0 contains a heap buffer overflow vulnerability in persistent_cache_read_entry_v3 that all
CVE-2026-109256 MEDIUM 5.3 UPGRADE FreeRDP 3.10.0 through 3.32.2 contains a heap buffer overflow in the WinPR png_write_data callback that writes
CVE-2026-109257 MEDIUM 5.9 DOWNGRADE FreeRDP before 3.32.0 contains a double-free vulnerability in nsc_context_initialize_encode() that leaves dang
CVE-2026-109940 MEDIUM 4.3 UPGRADE FreeRDP 3.0.0-beta1 before 3.32.0 on Unix builds with PKCS#11 support has a stack-based buffer overflow in wpr
CVE-2026-109939 MEDIUM 6.5 UPGRADE FreeRDP 3.27.1 before 3.32.0 contains a NULL pointer dereference in update_read_cache_bitmap_v3_order() in lib

References

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