Read the docs
TI-2026-21465 Aliases CVE-2026-26986

FreeRDP has heap-use-after-free in rail_window_free

Priority MEDIUM 58CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · None · Low
Fix status
Partial Red Hat: 23 fixed, 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat.

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `rail_window_free` dereferences a freed `xfAppWindow` pointer during `HashTable_Free` cleanup because `xf_rail_window_common` calls `free(appWindow)` on title allocation failure without first removing the entry from the `railWindows` hash table, leaving a dangling pointer that is freed again on disconnect. Version 3.23.0 fixes the vulnerability.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00557 46th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial FreeRDP (FreeRDP): 3.23.0Red Hat: 14 advisoriesRed Hat: 23 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
FreeRDPFreeRDPbefore 3.23.03.23.0Patch availableCNA
  • FreeRDP VendorFreeRDP Affected before 3.23.0 Fixed in 3.23.0 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*before 3.23.0VulnerableFreeRDP
  • cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:* Versions before 3.23.0 Vulnerable ·FreeRDP

Remediation

  • Fix · CNA FreeRDP (FreeRDP) Fixed in 3.23.0

Red Hat 14 advisories

  • RHSA-2026:20605 Released 2026-05-26 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) freerdp-2:3.10.3-3.el10_0.7, freerdp-libs-2:3.10.3-3.el10_0.7, libwinpr-2:3.10.3-3.el10_0.7
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) freerdp-devel-2:3.10.3-3.el10_0.7, freerdp-server-2:3.10.3-3.el10_0.7, libwinpr-devel-2:3.10.3-3.el10_0.7
  • RHSA-2026:20546 Released 2026-05-26 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) freerdp-2.1.1-5.el7_9.9, freerdp-libs-2.1.1-5.el7_9.9, freerdp-libs-2.1.1-5.el7_9.9.ppc +2
    • Red Hat Enterprise Linux Server Optional (v. 7 ELS) freerdp-devel-2.1.1-5.el7_9.9, freerdp-devel-2.1.1-5.el7_9.9.ppc, libwinpr-devel-2.1.1-5.el7_9.9 +1
  • RHSA-2026:19811 Released 2026-05-20 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) freerdp-2:2.2.0-14.el8_4, freerdp-libs-2:2.2.0-14.el8_4, libwinpr-2:2.2.0-14.el8_4 +1
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) freerdp-2:2.2.0-14.el8_4, freerdp-libs-2:2.2.0-14.el8_4, libwinpr-2:2.2.0-14.el8_4 +1
Show 11 more Red Hat advisories
  • RHSA-2026:19358 Released 2026-05-19 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux AppStream (v. 9) freerdp-2:2.11.7-7.el9_8.3, freerdp-libs-2:2.11.7-7.el9_8.3, libwinpr-2:2.11.7-7.el9_8.3
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) freerdp-devel-2:2.11.7-7.el9_8.3, libwinpr-devel-2:2.11.7-7.el9_8.3
  • RHSA-2026:19142 Released 2026-05-19 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux AppStream (v. 10) freerdp-2:3.10.3-12.el10_2.5, freerdp-libs-2:3.10.3-12.el10_2.5, libwinpr-2:3.10.3-12.el10_2.5
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) freerdp-devel-2:3.10.3-12.el10_2.5, freerdp-server-2:3.10.3-12.el10_2.5, libwinpr-devel-2:3.10.3-12.el10_2.5
  • RHSA-2026:16865 Released 2026-05-13 · Red Hat rating Moderate
    freerdp security update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) freerdp-devel-2:2.11.7-1.el9_6.10, libwinpr-devel-2:2.11.7-1.el9_6.10
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) freerdp-2:2.11.7-1.el9_6.10, freerdp-libs-2:2.11.7-1.el9_6.10, libwinpr-2:2.11.7-1.el9_6.10
  • RHSA-2026:16866 Released 2026-05-13 · Red Hat rating Moderate
    freerdp security update
    • Red Hat CodeReady Linux Builder EUS (v.9.4) freerdp-devel-2:2.11.2-1.el9_4.8, libwinpr-devel-2:2.11.2-1.el9_4.8
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) freerdp-2:2.11.2-1.el9_4.8, freerdp-libs-2:2.11.2-1.el9_4.8, libwinpr-2:2.11.2-1.el9_4.8
  • RHSA-2026:16814 Released 2026-05-13 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) freerdp-2:2.2.0-7.el8_6.8, freerdp-libs-2:2.2.0-7.el8_6.8, libwinpr-2:2.2.0-7.el8_6.8 +1
    • Red Hat Enterprise Linux AppStream E4S (v.8.6) freerdp-2:2.2.0-7.el8_6.8, freerdp-libs-2:2.2.0-7.el8_6.8, libwinpr-2:2.2.0-7.el8_6.8 +1
    • Red Hat Enterprise Linux AppStream TUS (v.8.6) freerdp-2:2.2.0-7.el8_6.8, freerdp-libs-2:2.2.0-7.el8_6.8, libwinpr-2:2.2.0-7.el8_6.8 +1
  • RHSA-2026:16777 Released 2026-05-13 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) freerdp-2:2.2.0-12.el8_8.8, freerdp-libs-2:2.2.0-12.el8_8.8, libwinpr-2:2.2.0-12.el8_8.8 +1
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) freerdp-2:2.2.0-12.el8_8.8, freerdp-libs-2:2.2.0-12.el8_8.8, libwinpr-2:2.2.0-12.el8_8.8 +1
  • RHSA-2026:16482 Released 2026-05-13 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux AppStream (v. 9) freerdp-2:2.11.7-1.el9_7.7, freerdp-libs-2:2.11.7-1.el9_7.7, libwinpr-2:2.11.7-1.el9_7.7
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) freerdp-devel-2:2.11.7-1.el9_7.7, libwinpr-devel-2:2.11.7-1.el9_7.7
  • RHSA-2026:16483 Released 2026-05-12 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) freerdp-2:2.4.1-6.el9_2.9, freerdp-libs-2:2.4.1-6.el9_2.9, libwinpr-2:2.4.1-6.el9_2.9
  • RHSA-2026:16485 Released 2026-05-12 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) freerdp-2:2.4.1-3.el9_0.7, freerdp-libs-2:2.4.1-3.el9_0.7, libwinpr-2:2.4.1-3.el9_0.7
  • RHSA-2026:16019 Released 2026-05-11 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux AppStream (v. 8) freerdp-2:2.11.7-9.el8_10, freerdp-libs-2:2.11.7-9.el8_10, libwinpr-2:2.11.7-9.el8_10 +1
    • Red Hat Enterprise Linux CRB (v. 8) freerdp-devel-2:2.11.7-9.el8_10
  • RHSA-2026:16014 Released 2026-05-11 · Red Hat rating Moderate
    freerdp security update
    • Red Hat Enterprise Linux AppStream (v. 10) freerdp-2:3.10.3-5.el10_1.8, freerdp-libs-2:3.10.3-5.el10_1.8, libwinpr-2:3.10.3-5.el10_1.8
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) freerdp-devel-2:3.10.3-5.el10_1.8, freerdp-server-2:3.10.3-5.el10_1.8, libwinpr-devel-2:3.10.3-5.el10_1.8

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix yet
Red Hat CodeReady Linux Builder EUS (v.9.4)Fixed RHSA-2026:16866
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:16865
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:16014, RHSA-2026:19142
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:16019
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:16482, RHSA-2026:19358
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:19811
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:16814
Red Hat Enterprise Linux AppStream E4S (v.8.6)Fixed RHSA-2026:16814
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:16777
Red Hat Enterprise Linux AppStream E4S (v.9.0)Fixed RHSA-2026:16485
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:16483
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:20605
Red Hat Enterprise Linux AppStream EUS (v.9.4)Fixed RHSA-2026:16866
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:16865
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:19811
Red Hat Enterprise Linux AppStream TUS (v.8.6)Fixed RHSA-2026:16814
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:16777
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:16019
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:16014, RHSA-2026:19142
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:16482, RHSA-2026:19358
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:20605
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2026:20546
Red Hat Enterprise Linux Server Optional (v. 7 ELS)Fixed RHSA-2026:20546

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-26986

References

Exploit 1

Patch 1

Other 6

  • TI-2026-85092 Use-after-free in FreeRDP rdpgfx channel close handling CVSS 4.0CRITICAL 9.3
  • TI-2026-85091 Out-of-bounds write in FreeRDP proxy via bitmap cache v2 capability CVSS 4.0CRITICAL 9.3
  • TI-2026-24435 FreeRDP has a `size_t` underflow in ADPCM decoder leads to heap-buffer-overflow write CVSS 3.1CRITICAL 9.8
  • TI-2023-21373 Out-Of-Bounds Write in FreeRDP CVSS 3.1CRITICAL 9.8
  • TI-2022-08692 Server side NTLM does not properly check parameters in FreeRDP CVSS 3.1CRITICAL 9.1
  • TI-2023-21374 Out-Of-Bounds Read in FreeRDP CVSS 3.1CRITICAL 9.1
See all 336 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences