CVE-2026-91948Public exploitNetwork attack vectorHinoki check available

Server memory corruption via channel tracker underflow

Published Sep 15, 2026 · Updated Sep 15, 2026

Out-of-bounds write in FreeRDP 3.28.0 through 3.30.0 allows remote authenticated users to corrupt server heap memory via an RDP channel. The server-side ChannelPduTracker retains an oversized-message offset, counts a zero-capacity read as consumed data, then underflows the next read size and overwrites adjacent live pointers. Exploitation requires an authenticated RDP client, a SHOW_PROTOCOL static channel, and an assertion-disabled build; it can crash the server or support code execution.

CVSS severity7.5
High
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds write in FreeRDP 3.28.0 through 3.30.0 allows remote authenticated users to corrupt server heap memory via an RDP channel. The server-side ChannelPduTracker retains an oversized-message offset, counts a zero-capacity read as consumed data, then underflows the next read size and overwrites adjacent live pointers. Exploitation requires an authenticated RDP client, a SHOW_PROTOCOL static channel, and an assertion-disabled build; it can crash the server or support code execution.

The record

CVE
CVE-2026-91948
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
FreeRDP
Product
FreeRDP
Classifications
CWE-787, CWE-191, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.28.0 <3.31.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

FreeRDP · FreeRDPversion=3.28.0 <3.31.0

Published CVSS scores

7.5FreeRDPCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-191Integer Underflow (Wrap or Wraparound)
T1210Exploitation of Remote Services

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo