Heap out-of-bounds read and write via monitor indices
Published Sep 15, 2026 · Updated Sep 15, 2026
Out-of-bounds heap access in FreeRDP 3.11.0 through 3.30.0 allows attackers to corrupt client memory via a crafted RDP file. xf_detect_monitors uses the first MonitorIds value as an index into rdpmonitors without first checking it against MonitorCount. Exploitation requires a user to open the file with the X11 xfreerdp client; the resulting access can crash the client or corrupt its heap.
Summary
What happened
Out-of-bounds heap access in FreeRDP 3.11.0 through 3.30.0 allows attackers to corrupt client memory via a crafted RDP file. xf_detect_monitors uses the first MonitorIds value as an index into rdpmonitors without first checking it against MonitorCount. Exploitation requires a user to open the file with the X11 xfreerdp client; the resulting access can crash the client or corrupt its heap.
The record
- CVE
- CVE-2026-91958
- Published
- Sep 15, 2026
- Updated
- Sep 15, 2026
- Vendor
- FreeRDP
- Product
- FreeRDP
- Classifications
- T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 15, 2026CVE publishedPublication date reported by the CVE source.
- Sep 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.11.0 <3.31.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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