CVE-2026-91958

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.19% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 9.2% of scored records. A rank, not a probability.

NVD base score

6.9 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD 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/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

NVD analysis status

Analyzed. NVD last modified this record on 2026-09-24.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-09-15 15:18Z1 MO AGO

Last updated

2026-09-15 15:59Z1 MO AGO

Reserved

2026-09-15

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

Medium (CVSS 6.9)

CNA 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

Weaknesses

• CWE-125Out-of-bounds ReadBase
• CWE-787Out-of-bounds WriteBase

Data version

5.2

Document digest

5684c85f17156eef3826978ac070754f20d9b7598d937b3fb9372252bdd533f7

• github.comGitHub Security Advisory (GHSA-23pf-q83q-x45r)https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-23pf-q83q-x45rvendor-advisory
• www.vulncheck.comVulnCheck Advisory: FreeRDP 3.11.0 through 3.30.0 Heap Buffer Overflow via Monitor Indexhttps://www.vulncheck.com/advisories/freerdp-3.11.0-through-3.30.0-heap-buffer-overflow-via-monitor-indexthird-party-advisory