What’s Vulnerable › Vulnerabilities

CVE-2026-85089: FreeRDP before 3.31.0 Information Disclosure via uninitialized heap memory

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-09-03 · updated 2026-09-09
• Weakness: CWE-908

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.

Affected products

• FreeRDP: from 3.0.0 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
• https://github.com/FreeRDP/FreeRDP/blob/3.30.0/libfreerdp/core/info.c#L1541
• https://github.com/FreeRDP/FreeRDP/commit/056cede398d71c1f2540baebc26ec3327a249301
• https://github.com/FreeRDP/FreeRDP/commit/483c9388119f06bac420d92053cff9ef94e83bea
• https://github.com/FreeRDP/FreeRDP/releases/tag/3.31.0
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-v649-94v2-p72q
• https://www.vulncheck.com/advisories/freerdp-before-3.31.0-information-disclosure-via-uninitialized-heap-memory
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-v649-94v2-p72q

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