CVE-2026-55564: FreeRDP is a free implementation of the Remote Desktop Protocol

Q: How do I fix CVE-2026-55564?

freerdp: upgrade to 3.27.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-55564 being exploited?

CVE-2026-55564 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-2026-55564 affect?

CVE-2026-55564 affects freerdp. Severity is medium (CVSS 5.4). FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, the glyph_cache_get function in libfreerdp/cache/glyph.c checks whether index is greater than cache->number instead of greater than or equal to it. A maliciou

Routine

MEDIUM 5.4UPGRADE

CVE-2026-55564 is a medium-severity flaw (CVSS 5.4) 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 3.27.0, the glyph_cache_get function in libfreerdp/cache/glyph.c checks whether index is greater than cache->number instead of greater than or equal to it. A malicious RDP server can use GLYPH_FRAGMENT_USE replay in update_process_glyph_fragments to make the default cache receive index 254 when cache->number is 254, reading one pointer beyond the entries array and dereferen

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-125, CWE-193
Published	2026-08-19
Last modified	2026-10-26

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

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-19 18:16 UTCPublished CVE record published
2026-10-26 11:10 UTCUpdated Record last modified

freerdp freerdp UPGRADE

Affected: < 3.27.0

Fixed in: 3.27.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 3.27.0 (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.

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-2026-55564?

freerdp: upgrade to 3.27.0. Exact commands for each OS are on this page.

Is CVE-2026-55564 being exploited?

CVE-2026-55564 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-2026-55564 affect?

CVE-2026-55564 affects freerdp. Severity is medium (CVSS 5.4). FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, the glyph_cache_get function in libfreerdp/cache/glyph.c checks whether index is greater than cache->number instead of greater than or equal to it. A maliciou

How urgent is CVE-2026-55564?

Priority 30/100. Public exploit reference

Software pages

WinRM and RDP vulnerabilities

Related CVEs

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
CVE-2026-109938 MEDIUM 6.5 UPGRADE Positive mapped-video coordinates overflow and abort FreeRDP clients A malicious or compromised RDP server can
CVE-2026-109941 MEDIUM 6.5 UPGRADE FreeRDP from 2.3.0 before 3.32.0 contains an infinite loop vulnerability in http_chuncked_read that allows mal
CVE-2026-109942 MEDIUM 6.5 UPGRADE FreeRDP 2.3.0 before 3.32.0 dereferences a NULL stream in rdg_process_close_packet in libfreerdp/core/gateway/

References

← Back to latest CVEs