Review reviewCritical

CVE-2026-67292

FreeRDP

FreeRDP before 3.29.0 contains a buffer over-disclosure vulnerability in the gateway WebSocket transport (libfreerdp/core/gateway/websocket.c). The client's Pong reply reuses a fixed 1024-byte response stream whose length is not sealed to the actual received Ping payload, so a malicious gateway/WebSocket peer sending a non-empty Ping control frame causes the client to reply with an overlong Pong that discloses bytes beyond the received payload (the peer receives the masking key and can unmask the reply). A zero-length Ping reaches an assertion and terminates the client (denial of service).

CVSS
9.3
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.08.01
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 9.3

Vulnerability overview

FreeRDP before 3.29.0 contains a buffer over-disclosure vulnerability in the gateway WebSocket transport (libfreerdp/core/gateway/websocket.c). The client's Pong reply reuses a fixed 1024-byte response stream whose length is not sealed to the actual received Ping payload, so a malicious gateway/WebSocket peer sending a non-empty Ping control frame causes the client to reply with an overlong Pong that discloses bytes beyond the received payload (the peer receives the masking key and can unmask the reply). A zero-length Ping reaches an assertion and terminates the client (denial of service).

Affected product and versions

Product
FreeRDP
Affected versions
< 3.29.0
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that FreeRDP and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE
CWE-130