Vulnpedia
← All CVEs

CVE-2026-91960

HIGH 7.1 PoC AVAILABLE ALL-YEARS

Published 2026-09-15 · Last modified 2026-09-15 · VulnCheck · NVD: Analyzed

FreeRDP versions before 3.31.0 contain an integer overflow in WinPR's Stream_EnsureRemainingCapacity function that allows remote attackers to cause denial of service. A malicious RD Gateway peer can send a WebSocket Ping frame with a crafted 64-bit extended payload length to trigger integer wraparound, resulting in a double free that crashes the FreeRDP client during connection.

EXPLOIT AVAILABLE

Public exploit or PoC code exists. The barrier to attack is reduced — watch closely.

Exploitation likelihood

0.5%chance of exploitation in 30 days · 38th percentile

○ In CISA KEV● Public exploit / PoC◆ SSVC: exploitation poc, automatable no

Impact if exploited

7.1CVSS 4.0 · HIGH · CNA

  • ConfidentialityNone
  • IntegrityNone
  • AvailabilityHigh

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓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

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-91960/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-2026-91960/poc.json

Affected

Vendors Freerdp

Products Freerdp

Weakness (CWE)

  • CWE-190: Integer Overflow or Wraparound

CVSS vector

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

Known Affected Software Configurations

VendorProductVersion range
FreerdpFreerdp< 3.31.0

All CVSS metrics

  • MEDIUM 6.5 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
  • HIGH 7.1 v4.0 · CNA Primary
    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
  • HIGH 7.1 v4.0 · NVD Secondary
    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/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 6.5 v3.1 · NVD Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References

Exploits & PoC

Advisories

Sources: NVD · CVE.org · EPSS