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Stack buffer overflow in FreeRDP PKCS#11 key name handling

Priority MEDIUM 56CWE-121Published · Updated

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

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00139 3rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial FreeRDP (FreeRDP): 3.32.0Red Hat: 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
FreeRDPFreeRDP3.0.0-beta1 to before 3.32.03.32.0Patch availableCNA
  • FreeRDP VendorFreeRDP Affected 3.0.0-beta1 to before 3.32.0 Fixed in 3.32.0 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*3.0.0 to before 3.32.0VulnerableFreeRDP
  • cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:* Versions 3.0.0 to before 3.32.0 Vulnerable ·FreeRDP

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 →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo 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

  1. 2026-10-13 Threatist record created from CVE-2026-109940
  2. 2026-10-13 Alias added: GHSA-9579-j8rw-69mx
  3. 2026-10-26 CVSS score added · NVD
  4. 2026-10-27 Affected versions changed · Red Hat
  5. 2026-10-27 CVSS score added · Red Hat

References

  • 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