CVE-2026-85089

MEDIUMCVSS 6.5/10EPSS 0.39%

Last modified

CVE-2026-85089 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. FreeRDP versions 3.0.0 through 3.30.0 (before 3.31.0) transmit uninitialized heap memory in Save Session Info PDU reserved padding fields. Three PDU writers in libfreerdp/core/info.c (rdp_write_logon_info_v2, rdp_write_logon_info_plain, and rdp_write_logon_info_ex) use Stream_Seek instead of Stream_Zero for reserved pad bytes (up to 576 bytes), leaving previously freed heap contents in the outgoing PDU. EPSS estimates a 0.39% chance of exploitation in the next 30 days.

Description

FreeRDP versions 3.0.0 through 3.30.0 (before 3.31.0) transmit uninitialized heap memory in Save Session Info PDU reserved padding fields. Three PDU writers in libfreerdp/core/info.c (rdp_write_logon_info_v2, rdp_write_logon_info_plain, and rdp_write_logon_info_ex) use Stream_Seek instead of Stream_Zero for reserved pad bytes (up to 576 bytes), leaving previously freed heap contents in the outgoing PDU. Because the send buffer is allocated with malloc (not zeroed), stale heap data — which may include cleartext credentials from prior sessions — can be sent to the receiving peer. FreeRDP-based servers using rdpUpdate::SaveSessionInfo and freerdp-proxy (which forwards these PDUs) are affected, allowing disclosure of server/proxy process memory to a downstream client.

Metrics

Weakness Enumeration

Affected Software

VendorProductVersions
FreerdpFreerdp>= 3.0.0, < 3.31.0

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-85089?
FreeRDP versions 3.0.0 through 3.30.0 (before 3.31.0) transmit uninitialized heap memory in Save Session Info PDU reserved padding fields. Three PDU writers in libfreerdp/core/info.c (rdp_write_logon_info_v2, rdp_write_logon_info_plain, and rdp_write_logon_info_ex) use Stream_Seek instead of Stream_Zero for reserved pad bytes (up to 576 bytes), leaving previously freed heap contents in the outgoing PDU. Because the send buffer is allocated with malloc (not zeroed), stale heap data — which may include cleartext credentials from prior sessions — can be sent to the receiving peer. FreeRDP-based servers using rdpUpdate::SaveSessionInfo and freerdp-proxy (which forwards these PDUs) are affected, allowing disclosure of server/proxy process memory to a downstream client.
How severe is CVE-2026-85089?
CVE-2026-85089 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.
How do I fix CVE-2026-85089?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST