High · CVSS 7.1CVE-2026-91953

FreeRDP before 3.31.0 Heap Buffer Overflow via LB_LOAD_BALANCE_INFOCVE-2026-91953

Answer in brief

CVE-2026-91953 records a High severity (CVSS 7.1) vulnerability in FreeRDP before 3.31.0 Heap Buffer Overflow via LB_LOAD_BALANCE_INFO. The current sources do not mark it as known exploited. The current feed maps FreeRDP/FreeRDP (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 15, 2026Updated Sep 24, 2026Source checked Oct 30, 2026First seen by HOL Sep 15, 2026Material review Sep 24, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.1
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps FreeRDP/FreeRDP (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:a:freerdp:freerdp::::::::	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
FreeRDP/FreeRDPgeneric	>=0 <3.31.0	3.31.0

Recommended response

Check inventory. Check lockfiles and deployed manifests for FreeRDP/FreeRDP.
Review the reported fix. Update FreeRDP/FreeRDP to 3.31.0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 15, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.