CVE-2026-91956

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

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, GitHub Security Advisory, a secondary CVSS source

Also known asEUVD-2026-78632 (ENISA EUVD) · GHSA-mh85-h6g9-mfcc (GitHub Security Advisories)Source: ENISA EUVD

6.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • 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
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
33rd
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track 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). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

September 15, 2026

Last Modified

September 24, 2026

Advisory Details (2)

Auto-updated Sep 15, 2026
Patch available. Sources: github.
Web page

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 advisoryMentions a patch (unverified)

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

Patch Availability(3)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatfreerdp-2:2.11.7-7.el9_8.82026-10-08redhat
redhatfreerdp-2:2.11.7-14.el8_102026-10-06redhat
redhatfreerdp-2:3.10.3-12.el10_2.142026-10-05redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

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 8× in last 7d / 58× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 110 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 11 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:36 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  4. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  5. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  6. 2026-10-27 18:25 UTCOSV refresh
  7. 2026-10-27 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  8. 2026-10-26 16:33 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  10. 2026-10-25 13:50 UTCEG score recompute
  11. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  14. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  15. 2026-10-20 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  16. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  17. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  18. 2026-10-18 03:00 UTCEG score recompute
  19. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  20. 2026-10-16 16:45 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  21. 2026-10-15 18:38 UTCEG score recompute
  22. 2026-10-15 18:38 UTCVendor advisory
  23. 2026-10-15 18:38 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  24. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  25. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
Show 74 more
  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  2. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  3. 2026-10-12 14:45 UTCEG score recompute
  4. 2026-10-11 19:13 UTCEG score recompute
  5. 2026-10-11 16:29 UTCEG score recompute
  6. 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  7. 2026-10-11 13:44 UTCEG score recompute
  8. 2026-10-11 05:40 UTCEG score recompute
  9. 2026-10-11 05:40 UTCVendor advisory
  10. 2026-10-11 05:40 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  11. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  12. 2026-10-10 00:24 UTCEG score recompute
  13. 2026-10-10 00:24 UTCVendor advisory
  14. 2026-10-10 00:24 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  15. 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  16. 2026-10-08 22:38 UTCEG score recompute
  17. 2026-10-08 22:38 UTCVendor advisory
  18. 2026-10-08 22:38 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  19. 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  20. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  21. 2026-10-07 14:34 UTCEG score recompute
  22. 2026-10-07 14:34 UTCVendor advisory
  23. 2026-10-07 14:33 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  24. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  25. 2026-10-06 12:02 UTCEG score recompute
  26. 2026-10-06 12:02 UTCVendor advisory
  27. 2026-10-06 12:02 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  28. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  29. 2026-10-05 10:17 UTCEG score recompute
  30. 2026-10-05 10:17 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  31. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  32. 2026-10-04 08:32 UTCEG score recompute
  33. 2026-10-04 08:32 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  34. 2026-10-03 06:47 UTCEG score recompute
  35. 2026-10-03 06:47 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  36. 2026-10-02 05:02 UTCEG score recompute
  37. 2026-10-02 05:02 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  38. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  39. 2026-10-01 02:58 UTCEG score recompute
  40. 2026-10-01 02:58 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  41. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  42. 2026-09-30 01:10 UTCEG score recompute
  43. 2026-09-30 01:10 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  44. 2026-09-28 20:13 UTCEG score recompute
  45. 2026-09-28 20:13 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  46. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  47. 2026-09-27 18:06 UTCEG score recompute
  48. 2026-09-27 18:06 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  49. 2026-09-27 13:49 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  50. 2026-09-26 16:20 UTCEG score recompute
  51. 2026-09-26 16:20 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  52. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  53. 2026-09-25 14:09 UTCEG score recompute
  54. 2026-09-25 14:09 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  55. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  56. 2026-09-24 12:18 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  57. 2026-09-24 03:19 UTCEG score recompute
  58. 2026-09-24 03:19 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  59. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  60. 2026-09-23 01:34 UTCEG score recompute
  61. 2026-09-23 01:34 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  62. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  63. 2026-09-21 23:48 UTCEG score recompute
  64. 2026-09-21 23:48 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  65. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  66. 2026-09-20 22:04 UTCEG score recompute
  67. 2026-09-20 22:04 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  68. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  69. 2026-09-19 20:18 UTCEG score recompute
  70. 2026-09-19 20:18 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  71. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  72. 2026-09-18 18:33 UTCEG score recompute
  73. 2026-09-18 18:33 UTCGHSA enrichmentGHSA-mh85-h6g9-mfcc · GitHub severity HIGH · GitHub CVSS 6.5
  74. 2026-09-18 17:29 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-91956?
CVE-2026-91956 is a medium-severity vulnerability; its CVE record was published on September 15, 2026. 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…
When was CVE-2026-91956 made public?
CVE-2026-91956 was made public on September 1, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on September 15, 2026. EchelonGraph's copy of the record carries a last-modified date of September 24, 2026; the record at its source may have been updated since.
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 (33rd 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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