# CVE-2026-91948

## Summary

- **CVE ID:** CVE-2026-91948
- **Severity:** HIGH
- **CVSS Score:** 7.7 (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)
- **CWE:** CWE-191
- **Published:** Sep 15, 2026
- **Last Modified:** Sep 17, 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.

## Affected Products

- FreeRDP — FreeRDP (3.28.0)
- FreeRDP — FreeRDP (3.31.0)

## References

- [CNA](https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9jcm-x588-gh26)
- [CNA](https://github.com/FreeRDP/FreeRDP/commit/40d9202cd95551600c07437ce6bd5ecd7d31e57b)
- [CNA](https://www.vulncheck.com/advisories/freerdp-before-3.31.0-out-of-bounds-write-via-show-protocol)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.65%
- **EPSS Percentile:** 49.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._