CVE-2026-91948

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-15. a secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: 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 server-side static virtual channel handling when CHANNEL_OPTION_SHOW_PROTOCOL is enabled. Authenticated clients can queue oversized channel messages that cause buffer underflow and corrupt heap memory including live pointers, potentially enabling code execution.

CVSS v3
7.5
EG Score
7.5(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
Severity75% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
50%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 17, 2026

Advisory Details (3)

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

FreeRDP before 3.31.0 Out-of-bounds Write via SHOW_PROTOCOL | Advisories | VulnCheck

https://www.vulncheck.com/advisories/freerdp-before-3.31.0-out-of-bounds-write-via-show-protocol
github_commit

commit 40d9202cd955 (FreeRDP/FreeRDP)

Fix landed in FreeRDP/FreeRDP commit 40d9202cd955 — awaiting tagged release

https://github.com/FreeRDP/FreeRDP/commit/40d9202cd95551600c07437ce6bd5ecd7d31e57b
github Patch Available🟡 PoC Available

FreeRDP #13102 security impact: SHOW_PROTOCOL live-pointer overwrite · Advisory · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9jcm-x588-gh26

Vendor Advisories for CVE-2026-91948(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 23× in last 7d / 23× 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 11:04 UTCGHSA enrichment
  2. 2026-09-18 23:23 UTCEG score recompute
  3. 2026-09-18 23:23 UTCGHSA enrichment
  4. 2026-09-18 19:28 UTCEPSS rescore
  5. 2026-09-18 11:42 UTCGHSA enrichment
  6. 2026-09-18 00:01 UTCEG score recompute
  7. 2026-09-18 00:01 UTCGHSA enrichment
  8. 2026-09-17 19:32 UTCEPSS rescore
  9. 2026-09-17 12:20 UTCEG score recompute
  10. 2026-09-17 12:20 UTCGHSA enrichment
  11. 2026-09-17 12:10 UTCEG score recompute
  12. 2026-09-17 12:10 UTCGHSA enrichment
  13. 2026-09-17 07:39 UTCGHSA enrichment
  14. 2026-09-16 19:57 UTCGHSA enrichment
  15. 2026-09-16 16:01 UTCEG score recompute
  16. 2026-09-16 16:01 UTCGHSA enrichment
  17. 2026-09-16 14:09 UTCEPSS rescore
  18. 2026-09-16 04:20 UTCEG score recompute
  19. 2026-09-16 04:20 UTCGHSA enrichment
  20. 2026-09-15 17:32 UTCEG score recompute
  21. 2026-09-15 16:18 UTCEG score recompute
  22. 2026-09-15 15:24 UTCEG score recompute
  23. 2026-09-15 15:22 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-91948?
CVE-2026-91948 is a high vulnerability published on September 15, 2026. FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in server-side static virtual channel handling when CHANNELOPTIONSHOW_PROTOCOL is enabled. Authenticated clients can queue oversized channel messages that cause buffer underflow and corrupt heap memory including live…
When was CVE-2026-91948 disclosed?
CVE-2026-91948 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-91948 actively exploited?
CVE-2026-91948 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 50.3% of all scored CVEs.
What is the CVSS score of CVE-2026-91948?
CVE-2026-91948 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-91948?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-91948, 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

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