CVE-2026-91948CWE-191

CVE-2026-91948

High · published September 15, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
47.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
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
EPSS
0.00590 · 47.5th percentile
Weakness
CWE-191 · Integer Underflow (Wrap or Wraparound)
Published
2026-09-15T20:17Z
References (3)
https://github.com/FreeRDP/FreeRDP/commit/40d9202cd95551600c07437ce6bd5ecd7d31e57b · [email protected]https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9jcm-x588-gh26 · [email protected]https://www.vulncheck.com/advisories/freerdp-before-3.31.0-out-of-bounds-write-via-show-protocol · [email protected]
EPSS history
Timeline
  • 17 SEP 03:33Z
    EPSS moved — → 1%
    epss
  • 15 SEP 15:18Z
    FreeRDP before 3.31.0 Out-of-bounds Write via SHOW_PROTOCOL
    cvelistv5