CVE-2026-91956

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 — 3 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: 0.4%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

FreeRDP before 3.31.0 contains an out-of-bounds read vulnerability in the URBDRC channel's func_get_ep_desc function that indexes interface arrays by position instead of protocol field InterfaceNumber. A malicious RDP server can send a crafted SELECT_CONFIGURATION message with permuted InterfaceNumber values to read past allocated heap memory and crash the client.

CVSS v3
6.5
EG Score
6.5MEDIUMhigh confidence
EG Risk
29
EG Risk 29/100CISA SSVC

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%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
29th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 15, 2026

Last Modified

September 24, 2026

Advisory Details (2)

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

FreeRDP before 3.31.0 Out-of-Bounds Read via URBDRC | Advisories | VulnCheck

https://www.vulncheck.com/advisories/freerdp-before-3.31.0-out-of-bounds-read-via-urbdrc
github Patch Available🟡 PoC Available

URBDRC out-of-bounds read in func_get_ep_desc via InterfaceNumber/array-position index mismatch · Advisory · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hg4r-vv53-vwf8

Vendor Advisories for CVE-2026-91956(1)

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

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
freerdp22.10.0+dfsg1-1 ... 2.11.7+dfsg1-6~deb12u1 (13 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
freerdp33.15.0+dfsg-2.1 ... 3.32.0+dfsg-1 (47 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
freerdp33.15.0+dfsg-2.1 ... 3.30.0+dfsg-1~bpo13+1 (40 versions)
  • every version up to 3.31.0+dfsg-1: fixed in 3.31.0+dfsg-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 58× 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. 2026-10-05 10:17 UTCEG score recompute
  2. 2026-10-05 10:17 UTCGHSA enrichment
  3. 2026-10-04 23:22 UTCEPSS rescore
  4. 2026-10-04 08:32 UTCEG score recompute
  5. 2026-10-04 08:32 UTCGHSA enrichment
  6. 2026-10-03 06:47 UTCEG score recompute
  7. 2026-10-03 06:47 UTCGHSA enrichment
  8. 2026-10-02 05:02 UTCEG score recompute
  9. 2026-10-02 05:02 UTCGHSA enrichment
  10. 2026-10-01 19:51 UTCEPSS rescore
  11. 2026-10-01 02:58 UTCEG score recompute
  12. 2026-10-01 02:58 UTCGHSA enrichment
  13. 2026-09-30 15:04 UTCEPSS rescore
  14. 2026-09-30 01:10 UTCEG score recompute
  15. 2026-09-30 01:10 UTCGHSA enrichment
  16. 2026-09-28 20:13 UTCEG score recompute
  17. 2026-09-28 20:13 UTCGHSA enrichment
  18. 2026-09-28 13:52 UTCEPSS rescore
  19. 2026-09-28 13:52 UTCEPSS rescore
  20. 2026-09-27 18:06 UTCEG score recompute
  21. 2026-09-27 18:06 UTCGHSA enrichment
  22. 2026-09-27 13:49 UTCEPSS rescore
  23. 2026-09-26 16:20 UTCEG score recompute
  24. 2026-09-26 16:20 UTCGHSA enrichment
  25. 2026-09-26 15:59 UTCEPSS rescore
Show 33 more
  1. 2026-09-25 14:09 UTCEG score recompute
  2. 2026-09-25 14:09 UTCGHSA enrichment
  3. 2026-09-24 14:04 UTCEPSS rescore
  4. 2026-09-24 12:18 UTCGHSA enrichment
  5. 2026-09-24 03:19 UTCEG score recompute
  6. 2026-09-24 03:19 UTCGHSA enrichment
  7. 2026-09-23 17:54 UTCEPSS rescore
  8. 2026-09-23 01:34 UTCEG score recompute
  9. 2026-09-23 01:34 UTCGHSA enrichment
  10. 2026-09-22 16:01 UTCEPSS rescore
  11. 2026-09-21 23:48 UTCEG score recompute
  12. 2026-09-21 23:48 UTCGHSA enrichment
  13. 2026-09-21 21:09 UTCEPSS rescore
  14. 2026-09-20 22:04 UTCEG score recompute
  15. 2026-09-20 22:04 UTCGHSA enrichment
  16. 2026-09-20 20:16 UTCEPSS rescore
  17. 2026-09-19 20:18 UTCEG score recompute
  18. 2026-09-19 20:18 UTCGHSA enrichment
  19. 2026-09-18 19:28 UTCEPSS rescore
  20. 2026-09-18 18:33 UTCEG score recompute
  21. 2026-09-18 18:33 UTCGHSA enrichment
  22. 2026-09-18 17:29 UTCEG score recompute
  23. 2026-09-18 17:29 UTCGHSA enrichment
  24. 2026-09-17 23:49 UTCEG score recompute
  25. 2026-09-17 23:49 UTCGHSA enrichment
  26. 2026-09-17 19:32 UTCEPSS rescore
  27. 2026-09-16 21:07 UTCGHSA enrichment
  28. 2026-09-16 18:18 UTCEG score recompute
  29. 2026-09-16 18:18 UTCGHSA enrichment
  30. 2026-09-16 14:09 UTCEPSS rescore
  31. 2026-09-15 16:33 UTCEG score recompute
  32. 2026-09-15 15:23 UTCEG score recompute
  33. 2026-09-15 15:22 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-91956?
CVE-2026-91956 is a medium vulnerability published on September 15, 2026. FreeRDP before 3.31.0 contains an out-of-bounds read vulnerability in the URBDRC channel's funcgetepdesc function that indexes interface arrays by position instead of protocol field InterfaceNumber. A malicious RDP server can send a crafted SELECTCONFIGURATION message with permuted InterfaceNumber…
When was CVE-2026-91956 disclosed?
CVE-2026-91956 was first published on September 15, 2026, with the most recent update on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-91956 actively exploited?
CVE-2026-91956 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (29th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-91956?
CVE-2026-91956 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-91956?
A fix for CVE-2026-91956 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-91956 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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