CVE-2026-22853: FreeRDP heap buffer overflow in RDPEAR NDR array reader

CVE-2026-22853 · Severity: critical · CVSS 9.8 · Published 2026-01-14

FreeRDP is an open-source tool used to connect to remote computers via the Remote Desktop Protocol (RDP). A security flaw in how the software handles certain data packets could allow a malicious server to crash the client application or potentially execute unauthorized code on the user's machine. This could lead to a full system compromise or the theft of sensitive data from the user's session.

Technologies: FreeRDP, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux AppStream. Vendors: FreeRDP, Red Hat.

Quick answers

Is CVE-2026-22853 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-22853 being exploited in the wild.
How severe is CVE-2026-22853?
Critical severity, with a CVSS score of 9.8, published 14 January 2026.
Which products and versions are affected?
FreeRDP < 3.20.1; Red Hat Enterprise Linux 6 6; Red Hat Enterprise Linux AppStream 10.0, 10.1, 10.2.
Is there a fix for CVE-2026-22853?
A patch was published on 2026-01-14: FreeRDP version 3.20.1 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-22853 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-22853?
Check whether you run FreeRDP, Red Hat Enterprise Linux 6 or Red Hat Enterprise Linux AppStream at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A heap-based buffer overflow exists in FreeRDP's RDPEAR (Remote Desktop Protocol Enhanced Authentication and RestrictedAdmin) component within the NDR (Network Data Representation) array reader. The function 'ndr_read_pointedMessageEx' allocates a buffer based on 'hints->count', but the subsequent call to 'ndr_read_uconformant_array' reads an element count directly from the network stream without verifying it against the allocated size. An attacker-controlled 'count' larger than the 'hints' value results in an out-of-bounds write during the uint8 array reading loop. This vulnerability can be triggered by a malicious RDP server or a man-in-the-middle attacker to achieve remote code execution or a denial-of-service on the client. The issue is resolved in version 3.20.1.

Affected products

  • FreeRDP FreeRDP < 3.20.1
  • Red Hat Red Hat Enterprise Linux AppStream 10.0, 10.1, 10.2
  • Red Hat Red Hat Enterprise Linux 6 6

Timeline

  • 2026-01-14: advisory: GitHub Security Advisory GHSA-47v9-p4gp-w5ch published
  • 2026-01-14: patched: FreeRDP version 3.20.1 released
  • 2026-01-14: disclosed: CVE-2026-22853 published
  • 2026-05-19: patched: Red Hat released security updates for RHEL 10

References

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