CVE-2026-91958
MEDIUM 6.9 PoC AVAILABLE ALL-YEARSFreeRDP versions before 3.31.0 fail to validate MonitorIds array values when parsing RDP connection files, allowing unbounded array indexing in xf_detect_monitors. Attackers can craft a malicious RDP file with an out-of-range selectedmonitors value to trigger out-of-bounds heap read and write operations when opened in xfreerdp.
EXPLOIT AVAILABLE
Public exploit or PoC code exists. The barrier to attack is reduced — watch closely.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 9th percentile
○ In CISA KEV● Public exploit / PoC◆ SSVC: exploitation poc, automatable no
Impact if exploited
6.9CVSS 4.0 · MEDIUM · CNA
- ConfidentialityLow
- IntegrityLow
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ✓Privileges: No account or privileges required
- ⚠User interaction: Succeeds with passive user activity
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- reference https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-23pf-q83q-x45r
- github-search https://github.com/search?q=%22CVE-2026-91958%22&type=repositories
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-91958/poc.jsonMachine-readable PoC index for this CVE (for automation).For defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-91958/poc.json
Weakness (CWE)
- CWE-125: Out-of-bounds Read
CVSS vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Freerdp | Freerdp | ≥ 3.11.0 and < 3.31.0 |
All CVSS metrics
- MEDIUM 6.9 v4.0 · CNA Primary
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N - MEDIUM 6.6 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H - MEDIUM 6.9 v4.0 · NVD Secondary
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - MEDIUM 6.6 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H