FreeRDP Certificate Identity Validation Bypass via tls_verify_certificate
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- Spoofing
- Confidentiality · integrity · availability
- High · High · None
- 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-295.
Summary
FreeRDP before 3.32.2 fails to validate server certificates correctly in tls_verify_certificate(), accepting the Common Name when Subject Alternative Name entries do not match and comparing IP literals against DNS strings. A man-in-the-middle attacker holding a certificate from a CA the client trusts can bypass server identity checks and intercept RDP sessions, including keystrokes, clipboard contents and screen content. CVSS 4.0 scores it 9.1 (Critical) under CWE-295 (Improper Certificate Validation), and Red Hat rates it Important.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
FreeRDP before 3.32.2 contains an improper certificate validation vulnerability in tls_verify_certificate() that accepts Common Name fallback despite non-matching SAN entries and matches IP literals against DNS strings. Man-in-the-middle attackers holding a certificate from a client-trusted CA can bypass server identity checks to intercept RDP sessions, including keystrokes, clipboard, and screen content.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Update FreeRDP to version 3.32.2 or later. Red Hat Enterprise Linux 6, 7, 8, 9 and 10 have no fix available yet.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA FreeRDP (FreeRDP) Fixed in 3.32.2
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
FreeRDP 3.32.2
27 records Highest priority Priority HIGH 3 HIGH, 11 MEDIUM, 13 LOW
Other records, highest priority first
- TI-2026-84268 Denial of service in FreeRDP WinPR PNG and JPEG image readersPriority HIGH 77
- TI-2026-84291 Denial of service in FreeRDP via oversized X.224 routing tokenPriority HIGH 69
- TI-2026-84280 Use-after-free in FreeRDP dyn-channel-dump modulePriority HIGH 69
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix yet |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Timeline
- 2026-11-03 Threatist record created from CVE-2026-121392
- 2026-11-03 Alias added: GHSA-j5xv-pp35-jwf5
- 2026-11-03 CISA SSVC decision points changed
- 2026-11-03 Priority changed: MEDIUM → LOW
- 2026-11-05 Priority changed: LOW → MEDIUM
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score added · Red Hat
References
More Freerdp vulnerabilities
- 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
Sources
- CVE-2026-121392 · CVE Program
- CVE-2026-121392 · NVD
- FIRST EPSS
- GHSA-j5xv-pp35-jwf5 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-121392 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences