CVE-2026-114043
Description
A flaw was found in FreeRDP. WinPR's clipboard PNG-to-CF_DIB synthesis allocates a bit-packed buffer for PNGs with bit depth below 8, while winpr_bitmap_write_buffer() copies rows assuming one byte per pixel. A malicious RDP server can send a crafted low-bit-depth PNG clipboard payload that, when pasted by the victim, discloses heap memory. This issue affects FreeRDP before 3.32.1 when WINPR_UTILS_IMAGE_PNG is enabled.
Statement
This issue is rated Moderate because a user must connect to a malicious RDP server and paste or otherwise retrieve the crafted clipboard image (UI:R). The impact is high confidentiality disclosure of adjacent heap memory, without integrity or availability impact in the assessed scenario. The vulnerable path requires WinPR PNG clipboard conversion (WINPR_UTILS_IMAGE_PNG), introduced in FreeRDP/WinPR 3.x. Red Hat Enterprise Linux 8 and 9 ship FreeRDP 2.x without this code path and are not affected.
Mitigation
Do not connect FreeRDP clients to untrusted RDP servers, and avoid pasting remote clipboard image content from untrusted sessions.
If clipboard redirection is unused, disable the CLIPRDR channel.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Red Hat CVSS v3 Score Explanation
RH agrees with CNA. AV:N — malicious RDP server. AC:L — crafted low-bit-depth PNG clipboard. PR:N. UI:R — victim must paste/retrieve clipboard image. S:U. C:H — megabytes of heap disclosed. I:N/A:N. Score 6.5 maps to Moderate. Applies where WINPR_UTILS_IMAGE_PNG is enabled (RHEL 10); RHEL 8/9 FreeRDP 2.x lack this path.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
