CVE-2026-91953CWE-120

CVE-2026-91953

Medium · published September 15, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
38.7
In the wild
Unconfirmed
What it is

FreeRDP versions before 3.31.0 contain a heap buffer overflow vulnerability in nego_send_negotiation_request() that fails to validate the LB_LOAD_BALANCE_INFO field length before writing to a fixed 512-byte buffer. A malicious RDP server or man-in-the-middle can send a Server Redirection PDU with an oversized LB_LOAD_BALANCE_INFO value to overflow the buffer with attacker-controlled content, causing denial of service or heap corruption before authentication completes.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS v4.0
7.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
EPSS
0.00458 · 38.7th percentile
Weakness
CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Published
2026-09-15T20:17Z
Affected products (1)
ProductVersionsFixed in
freerdp/freerdp< 3.31.03.31.0
References (2)
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-r9pv-ffph-6gg6 · [email protected]https://www.vulncheck.com/advisories/freerdp-before-3.31.0-heap-buffer-overflow-via-lb-load-balance-info · [email protected]
EPSS history
Timeline
  • 17 SEP 03:33Z
    EPSS moved — → 0%
    epss
  • 15 SEP 15:18Z
    FreeRDP before 3.31.0 Heap Buffer Overflow via LB_LOAD_BALANCE_INFO
    cvelistv5