CVE•Published 2026-01-19•Modified 2026-06-30•1 article on news•6 live references•NVD data

CVE-2026-23531Freerdp · Freerdp

Vulnerability data via NVD (ingested)

CVSS v3.1

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS percentile

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Weaknesses (CWE)

CWE-122Heap-based Buffer Overflow

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, in ClearCodec, when `glyphData` is present, `clear_decompress` calls `freerdp_image_copy_no_overlap` without validating the destination rectangle, allowing an out-of-bounds read/write via crafted RDPGFX surface updates. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

Timeline

Published 2026-01-19

Modified 2026-06-30

External references

NVD MITRE Exploit-DB Sploitus trickest/cve VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-23531

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Freerdp Freerdp"

All exposed Freerdp Freerdp instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Freerdp"

HTTP body or banner mentions "Freerdp" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-23531