CVE-2026-81627

HIGHPre-NVD 8.28.2
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (8th percentile of EPSS-scored CVEs). GitHub Security Advisory CVSS 6.7 is lower than this score; a lower GitHub score revises it only when its advisory is newer than the CVE record's last change, and this advisory (published 2026-09-18) is not newer than that change (2026-11-05), so it does not.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Elevated

Also known asEUVD-2026-82872 (ENISA EUVD) · GHSA-x7v7-qcr5-q66r (GitHub Security Advisories)Source: ENISA EUVD

8.2EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 8.2Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

A flaw was found in QEMU. The VAPIC setup hypercall in hw/i386/vapic.c does not validate that the writable RAM alias remains within the option ROM window. A privileged guest user on a Q35/KVM machine can position this alias over locked SMRAM, bypassing chipset D_LCK protection and injecting code into System Management Mode memory.

CVSS v3
8.2
EG Score
8.2HIGHmedium confidence
EG Risk
53
EG Risk 53/100

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)
Severity82% × 45%
Impact severity (EG Severity): CVSS 8.2 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.2%
EPSS %ILE
8th
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 (8.2): severity, escalated by confirmed exploitation. This CVE's 8.2 is its impact severity (EG Severity), not escalated.

EG Severity
8.2 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-11). 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 low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 14 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 low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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)14 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 total (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 18, 2026

Last Modified

November 5, 2026

Advisory Details (3)

Auto-updated Sep 18, 2026
Patch available. Sources: redhat.
Web page

VAPIC writable ROM alias can escape the option-ROM window and expose locked SMRAM (#4206) · Issues · QEMU / QEMU · GitLab

https://gitlab.com/qemu-project/qemu/-/work_items/4206
Red Hat

2536950 – (CVE-2026-81627) CVE-2026-81627 qemu-kvm: VAPIC writable ROM alias can escape the option-ROM window and expose locked SMRAM

https://bugzilla.redhat.com/show_bug.cgi?id=2536950
Red HatMentions a patch (unverified)

CVE-2026-81627 - 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-2026-81627

Vendor Advisories for CVE-2026-81627(2)

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
qemu1:10.0.0+ds-1 ... 1:9.2.2+ds-1~bpo12+1 (208 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
qemu1:10.0.10+ds-0+deb13u1 ... 1:11.1.3+ds-1 (75 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
qemu1:10.0.2+ds-2 ... 1:11.1.2+ds-1~bpo13+1 (57 versions)
  • every version up to 1:11.1.2+ds-1: fixed in 1:11.1.2+ds-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 41× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 183 rows 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. None are among the latest 100 rows. The 83 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:57 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  2. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  3. 2026-11-12 11:12 UTCEchelonGraph re-scored
  4. 2026-11-12 11:12 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub severity MODERATE · GitHub CVSS 6.7
  5. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  6. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  7. 2026-11-09 16:36 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  8. 2026-11-08 16:41 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  9. 2026-11-07 16:40 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  10. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  11. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  12. 2026-11-05 00:27 UTCEchelonGraph re-scored
  13. 2026-11-05 00:27 UTCVendor advisory
  14. 2026-11-05 00:27 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub severity MODERATE · GitHub CVSS 6.7
  15. 2026-11-04 23:50 UTCEchelonGraph re-scored
  16. 2026-11-04 23:50 UTCVendor advisory
  17. 2026-11-04 23:50 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub severity MODERATE · GitHub CVSS 6.7
  18. 2026-11-04 16:37 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  19. 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  20. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  21. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  22. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  23. 2026-10-30 20:26 UTCEchelonGraph re-scored
  24. 2026-10-30 20:26 UTCVendor advisory
  25. 2026-10-30 20:26 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
Show 75 more
  1. 2026-10-30 20:14 UTCEchelonGraph re-scored
  2. 2026-10-30 20:14 UTCVendor advisory
  3. 2026-10-30 20:14 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  4. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  5. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  6. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  7. 2026-10-28 12:48 UTCEchelonGraph re-scored
  8. 2026-10-28 12:48 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  9. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  10. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  11. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  12. 2026-10-25 13:58 UTCEchelonGraph re-scored
  13. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  14. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  15. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  16. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  17. 2026-10-20 18:07 UTCEchelonGraph re-scored
  18. 2026-10-20 18:06 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  19. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  20. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  21. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  22. 2026-10-18 03:09 UTCEchelonGraph re-scored
  23. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  24. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  25. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  26. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  27. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  28. 2026-10-13 06:18 UTCEchelonGraph re-scored
  29. 2026-10-13 06:18 UTCVendor advisory
  30. 2026-10-13 06:18 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  31. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  32. 2026-10-12 14:56 UTCEchelonGraph re-scored
  33. 2026-10-12 01:48 UTCVendor advisory
  34. 2026-10-12 01:48 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  35. 2026-10-11 19:20 UTCEchelonGraph re-scored
  36. 2026-10-11 16:37 UTCEchelonGraph re-scored
  37. 2026-10-11 14:07 UTCVendor advisory
  38. 2026-10-11 14:07 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  39. 2026-10-11 13:54 UTCEchelonGraph re-scored
  40. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  41. 2026-10-11 02:48 UTCEchelonGraph re-scored
  42. 2026-10-11 02:48 UTCVendor advisory
  43. 2026-10-11 02:48 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  44. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  45. 2026-10-10 14:47 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  46. 2026-10-10 03:27 UTCEchelonGraph re-scored
  47. 2026-10-10 03:27 UTCVendor advisory
  48. 2026-10-10 03:27 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  49. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  50. 2026-10-09 16:09 UTCVendor advisory
  51. 2026-10-09 16:09 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  52. 2026-10-09 04:51 UTCVendor advisory
  53. 2026-10-09 04:51 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  54. 2026-10-08 17:32 UTCVendor advisory
  55. 2026-10-08 17:31 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  56. 2026-10-08 01:43 UTCEchelonGraph re-scored
  57. 2026-10-08 01:43 UTCVendor advisory
  58. 2026-10-08 01:43 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  59. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  60. 2026-10-07 14:25 UTCVendor advisory
  61. 2026-10-07 14:25 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  62. 2026-10-07 03:00 UTCVendor advisory
  63. 2026-10-07 03:00 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  64. 2026-10-06 15:42 UTCEchelonGraph re-scored
  65. 2026-10-06 15:42 UTCVendor advisory
  66. 2026-10-06 15:42 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  67. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  68. 2026-10-06 04:10 UTCEchelonGraph re-scored
  69. 2026-10-06 04:10 UTCVendor advisory
  70. 2026-10-06 04:09 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  71. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  72. 2026-10-05 16:36 UTCVendor advisory
  73. 2026-10-05 16:36 UTCGHSA enrichmentGHSA-x7v7-qcr5-q66r · GitHub CVSS 6.7
  74. 2026-10-05 05:19 UTCEchelonGraph re-scored
  75. 2026-10-05 05:19 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-81627?
CVE-2026-81627 is a high-severity vulnerability; its CVE record was published on September 18, 2026. A flaw was found in QEMU. The VAPIC setup hypercall in hw/i386/vapic.c does not validate that the writable RAM alias remains within the option ROM window. A privileged guest user on a Q35/KVM machine can position this alias over locked SMRAM, bypassing chipset D_LCK protection and injecting code…
When was CVE-2026-81627 made public?
CVE-2026-81627 was made public on August 26, 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 September 18, 2026. EchelonGraph's copy of the record carries a last-modified date of November 5, 2026; the record at its source may have been updated since.
Is CVE-2026-81627 actively exploited?
CVE-2026-81627 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (8th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-81627?
CVE-2026-81627 has a CVSS base score of 8.2 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-81627?
A fix for CVE-2026-81627 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-81627 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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