CVE-2026-91951

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-15. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in the urbdrc client channel's urb_send_current_frame_number_result() function. A malicious RDP server can send a crafted 28-byte USB redirection message to trigger a 4-byte write past the allocated 16-byte buffer, causing denial of service when verbose asserts are enabled.

CVSS v3
6.5
EG Score
6.5(high)
EG Risk
34(Track)
EG Risk 34/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity65% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
28%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 16, 2026

Advisory Details (2)

Auto-updated Sep 15, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

FreeRDP 3.14.0 through 3.30.0 Out-of-bounds Write via urbdrc | Advisories | VulnCheck

https://www.vulncheck.com/advisories/freerdp-3.14.0-through-3.30.0-out-of-bounds-write-via-urbdrc
github Patch Available🟡 PoC Available

Out-of-bounds write in urb_send_current_frame_number_result (urbdrc client channel) · Advisory · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-h5w2-q35j-443h

Vendor Advisories for CVE-2026-91951(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 15× in last 7d / 15× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 21:09 UTCEG score recompute
  2. 2026-09-19 21:08 UTCGHSA enrichment
  3. 2026-09-18 21:15 UTCEG score recompute
  4. 2026-09-18 21:15 UTCGHSA enrichment
  5. 2026-09-18 19:28 UTCEPSS rescore
  6. 2026-09-17 21:00 UTCEG score recompute
  7. 2026-09-17 21:00 UTCGHSA enrichment
  8. 2026-09-17 19:32 UTCEPSS rescore
  9. 2026-09-16 21:07 UTCGHSA enrichment
  10. 2026-09-16 17:55 UTCEG score recompute
  11. 2026-09-16 17:55 UTCGHSA enrichment
  12. 2026-09-16 14:09 UTCEPSS rescore
  13. 2026-09-15 16:33 UTCEG score recompute
  14. 2026-09-15 15:23 UTCEG score recompute
  15. 2026-09-15 15:22 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-91951?
CVE-2026-91951 is a medium vulnerability published on September 15, 2026. FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in the urbdrc client channel's urbsendcurrentframenumber_result() function. A malicious RDP server can send a crafted 28-byte USB redirection message to trigger a 4-byte write past the allocated 16-byte buffer, causing…
When was CVE-2026-91951 disclosed?
CVE-2026-91951 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-91951 actively exploited?
CVE-2026-91951 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 71.8% of all scored CVEs.
What is the CVSS score of CVE-2026-91951?
CVE-2026-91951 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-91951?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-91951, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-91951

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