Heap buffer overflow in FreeRDP WinPR PNG conversion
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Deferred Red Hat: fix deferred
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-122 and the CVSS impact.
Summary
FreeRDP 3.10.0 through 3.32.2 contains a heap buffer overflow in the WinPR png_write_data callback (CWE-122) that writes past the buffer after a realloc failure. A malicious RDP clipboard peer can supply a large CF_DIB image that triggers an out-of-bounds memcpy during PNG conversion, crashing the client. A public exploit is linked in the references.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
FreeRDP 3.10.0 through 3.32.2 contains a heap buffer overflow in the WinPR png_write_data callback that writes past the buffer after a realloc failure. A malicious RDP clipboard peer can supply a large CF_DIB image that triggers out-of-bounds memcpy during PNG conversion, causing a client 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
The sources list no fixed version for FreeRDP.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
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
- 2026-10-12 Threatist record created from CVE-2026-109256
- 2026-10-12 Alias added: GHSA-h8f2-6xfm-5cjf
- 2026-10-13 Affected versions changed · Red Hat
- 2026-10-13 CVSS score added · Red Hat
- 2026-10-13 Priority changed: MEDIUM → LOW
- 2026-10-15 Affected versions changed · Red Hat
- 2026-10-18 CISA SSVC decision points changed
- 2026-10-18 Priority changed: LOW → MEDIUM
- 2026-10-27 CVSS score added · NVD
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-2026-109256 · CVE Program
- CVE-2026-109256 · NVD
- FIRST EPSS
- GHSA-h8f2-6xfm-5cjf · GitHub Advisory Database · CC BY 4.0
- CVE-2026-109256 · Red Hat security data · CC BY 4.0
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