What’s Vulnerable › Vulnerabilities

CVE-2026-91958: FreeRDP 3.11.0 through 3.30.0 Heap Buffer Overflow via Monitor Index

• Severity: medium (CVSS 6.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-09-15 · updated 2026-09-24
• Weakness: CWE-125

Description

FreeRDP versions before 3.31.0 fail to validate MonitorIds array values when parsing RDP connection files, allowing unbounded array indexing in xf_detect_monitors. Attackers can craft a malicious RDP file with an out-of-range selectedmonitors value to trigger out-of-bounds heap read and write operations when opened in xfreerdp.

Affected products

• FreeRDP: from 3.11.0 before 3.31.0 — fixed in 3.31.0

How to fix

Upgrade to a fixed version: FreeRDP 3.31.0. Check the vendor advisory for mitigations.

References

• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-23pf-q83q-x45r
• https://www.vulncheck.com/advisories/freerdp-3.11.0-through-3.30.0-heap-buffer-overflow-via-monitor-index
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-23pf-q83q-x45r

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