CVE-2026-85089
FreeRDP before 3.31.0 Information Disclosure via uninitialized heap memory
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.
INFO
Published Date :
Sept. 3, 2026, 1:06 p.m.
Last Modified :
Sept. 9, 2026, 7:12 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update FreeRDP to version 3.31.0 or later.
- Apply vendor patches if available.
- Review server and proxy configurations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-85089.
| URL | Resource |
|---|---|
| https://github.com/FreeRDP/FreeRDP | Product |
| https://github.com/FreeRDP/FreeRDP/blob/3.30.0/libfreerdp/core/info.c#L1541 | Product |
| https://github.com/FreeRDP/FreeRDP/commit/056cede398d71c1f2540baebc26ec3327a249301 | Patch |
| https://github.com/FreeRDP/FreeRDP/commit/483c9388119f06bac420d92053cff9ef94e83bea | Patch |
| https://github.com/FreeRDP/FreeRDP/releases/tag/3.31.0 | Product Release Notes |
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-v649-94v2-p72q | Exploit Mitigation Vendor Advisory |
| https://www.vulncheck.com/advisories/freerdp-before-3.31.0-information-disclosure-via-uninitialized-heap-memory | Patch Release Notes Third Party Advisory |
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-v649-94v2-p72q | Exploit Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-85089 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-85089
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-85089 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-85089 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Sep. 09, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:* versions from (including) 3.0.0 up to (excluding) 3.31.0 Added Reference Type VulnCheck: https://github.com/FreeRDP/FreeRDP Types: Product Added Reference Type VulnCheck: https://github.com/FreeRDP/FreeRDP/blob/3.30.0/libfreerdp/core/info.c#L1541 Types: Product Added Reference Type VulnCheck: https://github.com/FreeRDP/FreeRDP/commit/056cede398d71c1f2540baebc26ec3327a249301 Types: Patch Added Reference Type VulnCheck: https://github.com/FreeRDP/FreeRDP/commit/483c9388119f06bac420d92053cff9ef94e83bea Types: Patch Added Reference Type VulnCheck: https://github.com/FreeRDP/FreeRDP/releases/tag/3.31.0 Types: Product, Release Notes Added Reference Type CISA-ADP: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-v649-94v2-p72q Types: Exploit, Mitigation, Vendor Advisory Added Reference Type VulnCheck: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-v649-94v2-p72q Types: Exploit, Mitigation, Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/freerdp-before-3.31.0-information-disclosure-via-uninitialized-heap-memory Types: Patch, Release Notes, Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 03, 2026
Action Type Old Value New Value Added Reference https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-v649-94v2-p72q Added SSVC {'id': 'CVE-2026-85089', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-03T13:58:31.244942Z'} -
New CVE Received by [email protected]
Sep. 03, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/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 Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-908 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/85xxx/CVE-2026-85089.json">CVE-2026-85089</a> Added Reference https://github.com/FreeRDP/FreeRDP Added Reference https://github.com/FreeRDP/FreeRDP/blob/3.30.0/libfreerdp/core/info.c#L1541 Added Reference https://github.com/FreeRDP/FreeRDP/commit/056cede398d71c1f2540baebc26ec3327a249301 Added Reference https://github.com/FreeRDP/FreeRDP/commit/483c9388119f06bac420d92053cff9ef94e83bea Added Reference https://github.com/FreeRDP/FreeRDP/releases/tag/3.31.0 Added Reference https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-v649-94v2-p72q Added Reference https://www.vulncheck.com/advisories/freerdp-before-3.31.0-information-disclosure-via-uninitialized-heap-memory