CVE-2026-91948
FreeRDP before 3.31.0 Out-of-bounds Write via SHOW_PROTOCOL
- State
- Published
- Severity
- 7.7 High
- Published
- Sep 15, 2026
- Updated
- Sep 17, 2026
- Reserved
- Sep 15, 2026
Description
FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in server-side static virtual channel handling when CHANNEL_OPTION_SHOW_PROTOCOL is enabled. Authenticated clients can queue oversized channel messages that cause buffer underflow and corrupt heap memory including live pointers, potentially enabling code execution.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.7 High | CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H | VulnCheck |
Weaknesses
- CWE-191 Integer Underflow (Wrap or Wraparound)
Affected Products
| Product | Versions |
|---|---|
FreeRDPFreeRDP |
|
References
- GitHub Security Advisory (GHSA-9jcm-x588-gh26)vendor-advisory
- Patch Commitpatch
- VulnCheck Advisory: FreeRDP before 3.31.0 Out-of-bounds Write via SHOW_PROTOCOLthird-party-advisory
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