TI-2026-26302 Aliases CVE-2026-33952

FreeRDP: DoS via WINPR_ASSERT in rts_read_auth_verifier_no_checks

MEDIUM 60CWE-617Published 2026-03-30 · Updated 2026-04-02

Key facts

Attack vector: Network
Privileges required: None
User interaction: Passive
Attack complexity: High
Attack requirements: None
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 5 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-617.

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, an unvalidated auth_length field read from the network triggers a WINPR_ASSERT() failure in rts_read_auth_verifier_no_checks(), causing any FreeRDP client connecting through a malicious RDP Gateway to crash with SIGABRT. This is a pre-authentication denial of service affecting all FreeRDP clients using RPC-over-HTTP gateway transport. The assertion is active in default release builds (WITH_VERBOSE_WINPR_ASSERT=ON). This issue has been patched in version 3.24.2.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00282 20th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Partial FreeRDP (FreeRDP): 3.24.2Red Hat: 5 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

Vendor	Product	Affected versions	Fixed in	Status	Source
FreeRDP	FreeRDP	before 3.24.2	3.24.2	Patch available	CNA

FreeRDP VendorFreeRDP Affected before 3.24.2 Fixed in 3.24.2 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:freerdp:freerdp::::::::	before 3.24.2	Vulnerable	FreeRDP

cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:* Versions before 3.24.2 Vulnerable ·FreeRDP

Remediation

Fix · CNA FreeRDP (FreeRDP) Fixed in 3.24.2

Vendor assessments

Red Hat

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

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 6	Affected	No fix planned: Out of support scope
Red Hat Enterprise Linux 7	Affected	No fix planned: Out of support scope
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet: Fix deferred

Timeline

2026-10-02 Threatist record created from CVE-2026-33952

References

Exploit 1

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4v4p-9v5x-hc93

Patch 1

https://github.com/FreeRDP/FreeRDP/commit/4ac0b6467d371a1ad47c1f751c5b305e4c068adb

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