Security readout for executives and security teams
Plain-English summary
FreeRDP before 3.23.0 has a memory-safety bug that can crash or destabilize the X11 client during RDP RemoteApp/RAIL window handling. The published impact is limited to availability, not data theft or system takeover. Upgrade planning is warranted for environments using FreeRDP clients, especially with less-trusted RDP servers.
Executive priority
Schedule remediation in the normal patch cycle, with faster action for FreeRDP clients connecting to untrusted RDP servers. This is not presented as a data-breach vulnerability, but client crashes can disrupt remote access operations.
Technical view
CVE-2026-25952 is a CWE-416 heap-use-after-free in xf_SetWindowMinMaxInfo. xf_rail_get_window returns an unprotected xfAppWindow pointer from railWindows, while another thread can delete that window concurrently. FreeRDP fixed this in version 3.23.0. CVSS v4 is 5.5 with low availability impact.
Likely exposure
Systems running FreeRDP versions earlier than 3.23.0 are affected. Exposure appears most relevant to the X11 client RAIL/RemoteApp window-management path. Confirm packaged, embedded, or bundled FreeRDP versions across Linux workstations, jump hosts, thin clients, and administrative tooling.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. The vulnerability is network-reachable in the CVSS vector and requires no privileges or user interaction, but the stated impact is limited to availability. Treat untrusted or compromised RDP server connections as higher-risk.
Researcher notes
The race involves railWindows lookup and concurrent window deletion. The advisory identifies commit 1994e9844212a6dfe0ff12309fef520e888986b5 as the fix. Available evidence supports availability impact only; no source in the bundle confirms real-world exploitation.
Mitigation direction
- Upgrade FreeRDP to version 3.23.0 or later.
- Prioritize systems that connect to external or less-trusted RDP servers.
- Check operating system and vendor package advisories for backported fixes.
- If upgrade timing is uncertain, reduce unnecessary FreeRDP RAIL/RemoteApp usage where feasible.
Validation and detection
- Inventory installed and bundled FreeRDP versions.
- Flag any FreeRDP version earlier than 3.23.0.
- Confirm whether affected systems use the X11 client and RAIL/RemoteApp workflows.
- Verify patched packages map to FreeRDP 3.23.0 or include the upstream fix.
- Monitor vendor advisories for distribution-specific remediation status.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-416: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-25952 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.5 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
5.5MediumVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-cgqm-cwjg-7w9xCVE reference · x_refsource_CONFIRM
- https://github.com/FreeRDP/FreeRDP/commit/1994e9844212a6dfe0ff12309fef520e888986b5CVE reference · x_refsource_MISC
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_rail.c#L1174CVE reference · x_refsource_MISC
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_window.c#L1128CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.