CVE-2026-5164

MEDIUMNVD 5.56.7
EchelonGraph scoreMEDIUM confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score 6.7 from GitHub Security Advisory published 2026-03-30. NVD baseline CVSS 5.5; sources differ by 1.2.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3

Also known asEUVD-2026-17111 (ENISA EUVD) · GHSA-6457-73j6-h3qg (GitHub Security Advisories)Source: ENISA EUVD

6.7EG
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: 0.1%CVSS: 5.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A flaw was found in virtio-win. The RhelDoUnMap() function does not properly validate the number of descriptors provided by a user during an unmap request. A local user could exploit this input validation vulnerability by supplying an excessive number of descriptors, leading to a buffer overrun. This can cause a system crash, resulting in a Denial of Service (DoS).

CVSS v3
5.5
EG Score
6.7MEDIUMmedium confidence
EG Risk
30
EG Risk 30/100

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)
Severity67% × 45%
Impact severity (EG Severity): CVSS 6.7 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 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
0.1%
EPSS %ILE
1st
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 (6.7): severity, escalated by confirmed exploitation. This CVE's 6.7 is its impact severity (EG Severity), not escalated.

EG Severity
6.7 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.1% 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: 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.

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

March 30, 2026

Last Modified

June 17, 2026

Advisory Details (3)

Auto-updated Aug 6, 2026
Patch available. Sources: redhat, github_pr.
GitHub pull request Patch Available

viostor: Fix buffer overrun in unmap code

Patch available: virtio-win/kvm-guest-drivers-windows mm316 (PR #1504 merged 2026-02-02)

https://github.com/virtio-win/kvm-guest-drivers-windows/pull/1504
Red Hat

2453014 – (CVE-2026-5164) CVE-2026-5164 virtio-win: virtio-win: Denial of Service via unvalidated descriptor count in unmap request

https://bugzilla.redhat.com/show_bug.cgi?id=2453014
Red HatMentions a patch (unverified)

CVE-2026-5164 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-5164

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 37× 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 188 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 89 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  2. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  3. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  4. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  5. 2026-10-25 14:21 UTCEG score recompute
  6. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  7. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  8. 2026-10-22 22:53 UTCEG score recompute
  9. 2026-10-22 22:53 UTCGHSA enrichmentGHSA-6457-73j6-h3qg · GitHub CVSS 6.7
  10. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  11. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
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  14. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  15. 2026-10-18 03:32 UTCEG score recompute
  16. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  17. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  18. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
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  20. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  21. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  22. 2026-10-12 15:58 UTCEG score recompute
  23. 2026-10-11 19:41 UTCEG score recompute
  24. 2026-10-11 16:56 UTCEG score recompute
  25. 2026-10-11 14:20 UTCEG score recompute
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  1. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 4th percentile
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  10. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 4th percentile
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  12. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 4th percentile
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  16. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.1% · 1st percentile
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  37. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.1% · 1st percentile
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  39. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  40. 2026-08-16 09:47 UTCEG score recompute
  41. 2026-08-16 09:47 UTCGHSA enrichmentGHSA-6457-73j6-h3qg · GitHub CVSS 6.7
  42. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  43. 2026-08-14 06:10 UTCEG score recompute
  44. 2026-08-14 06:10 UTCGHSA enrichmentGHSA-6457-73j6-h3qg · GitHub CVSS 6.7
  45. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  46. 2026-08-12 20:29 UTCEG score recompute
  47. 2026-08-12 20:29 UTCGHSA enrichmentGHSA-6457-73j6-h3qg · GitHub CVSS 6.7
  48. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  49. 2026-08-11 05:05 UTCEG score recompute
  50. 2026-08-11 05:05 UTCGHSA enrichmentGHSA-6457-73j6-h3qg · GitHub CVSS 6.7
  51. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  52. 2026-08-10 05:24 UTCEG score recompute
  53. 2026-08-10 05:24 UTCGHSA enrichmentGHSA-6457-73j6-h3qg · GitHub CVSS 6.7
  54. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  55. 2026-08-09 05:44 UTCEG score recompute
  56. 2026-08-09 05:44 UTCGHSA enrichmentGHSA-6457-73j6-h3qg · GitHub CVSS 6.7
  57. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  58. 2026-08-07 15:55 UTCEG score recompute
  59. 2026-08-07 15:55 UTCGHSA enrichmentGHSA-6457-73j6-h3qg · GitHub CVSS 6.7
  60. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  61. 2026-08-06 00:40 UTCEG score recompute
  62. 2026-08-06 00:40 UTCGHSA enrichmentGHSA-6457-73j6-h3qg · GitHub CVSS 6.7
  63. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  64. 2026-08-03 23:00 UTCEG score recompute
  65. 2026-08-03 23:00 UTCGHSA enrichmentGHSA-6457-73j6-h3qg · GitHub CVSS 6.7
  66. 2026-08-03 10:36 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  67. 2026-08-02 15:03 UTCEG score recompute
  68. 2026-08-02 15:03 UTCGHSA enrichmentGHSA-6457-73j6-h3qg · GitHub CVSS 6.7
  69. 2026-08-02 02:27 UTCEPSS rescoreEPSS 0.1% · 1st percentile
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Frequently asked(5)

What is CVE-2026-5164?
CVE-2026-5164 is a medium-severity vulnerability; its CVE record was published on March 30, 2026. A flaw was found in virtio-win. The RhelDoUnMap() function does not properly validate the number of descriptors provided by a user during an unmap request. A local user could exploit this input validation vulnerability by supplying an excessive number of descriptors, leading to a buffer overrun.…
When was CVE-2026-5164 made public?
CVE-2026-5164 was made public on March 30, 2026: that is the date its CVE record's CNA, Red Hat, Inc., gives for when the vulnerability was made public. The CVE record itself was published on March 30, 2026. EchelonGraph's copy of the record carries a last-modified date of June 17, 2026; the record at its source may have been updated since.
Is CVE-2026-5164 actively exploited?
CVE-2026-5164 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-5164?
CVE-2026-5164 has a CVSS v3 base score of 5.5 (NVD). EchelonGraph synthesises NVD + FIRST EPSS + GHSA into a combined EG score of 6.7 (MEDIUM).
How do I remediate CVE-2026-5164?
A fix for CVE-2026-5164 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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