Stack buffer overflow in FreeRDP PKCS#11 key name handling
Key facts
- Attack vector
- Physical
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-121 and the CVSS impact.
Summary
FreeRDP from 3.0.0-beta1 before 3.32.0 on Unix builds with PKCS#11 support has a stack-based buffer overflow (CWE-121) in wprintKeyName() in WinPR's NCrypt PKCS#11 provider. It hex-encodes a key's CKA_ID, which can be up to 64 bytes, into a fixed 128-byte stack buffer. An attacker who supplies a malicious PKCS#11 token or module with a 55- to 64-byte CKA_ID can overflow the client's stack during key enumeration, crashing it.
Written with Claude Haiku 5.5 from the sources below · 2026-10-27
Description from the CNA
FreeRDP 3.0.0-beta1 before 3.32.0 on Unix builds with PKCS#11 support has a stack-based buffer overflow in wprintKeyName() in WinPR's NCrypt PKCS#11 provider. It hex-encodes a key's CKA_ID, which can be up to 64 bytes, into a fixed 128-byte stack buffer. An attacker supplying a malicious PKCS#11 token or module whose key and matching certificate use a 55- to 64-byte CKA_ID can overflow the client's stack during key enumeration, causing a crash.
Why it matters now
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
Remediation
Update FreeRDP to version 3.32.0. Red Hat Enterprise Linux 10 is affected without a fix; the sources list no fixed version for it.
Written with Claude Haiku 5.5 from the sources below · 2026-10-27
- Fix · CNA FreeRDP (FreeRDP) Fixed in 3.32.0
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
FreeRDP 3.32.0
20 records Highest priority Priority HIGH 1 HIGH, 15 MEDIUM, 4 LOW
Other records, highest priority first
- TI-2026-71718 Heap buffer over-read in FreeRDP proxy DRDYNVC channel name handlingPriority HIGH 70
- TI-2026-71714 Unbounded memory allocation in FreeRDP drive redirection readsPriority MEDIUM 64
- TI-2026-71713 Reachable assertion in FreeRDP lets a malicious server crash clientsPriority MEDIUM 64
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 |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-13 Threatist record created from CVE-2026-109940
- 2026-10-13 Alias added: GHSA-9579-j8rw-69mx
- 2026-10-26 CVSS score added · NVD
- 2026-10-27 Affected versions changed · Red Hat
- 2026-10-27 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-2026-109940 · CVE Program
- CVE-2026-109940 · NVD
- FIRST EPSS
- GHSA-9579-j8rw-69mx · GitHub Advisory Database · CC BY 4.0
- CVE-2026-109940 · Red Hat security data · CC BY 4.0
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