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 (2026-10-30), so it does not.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this weekElevated

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 2026-10-30). 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

October 30, 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

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 (200 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
qemu1:10.0.10+ds-0+deb13u1 ... 1:11.1.2+ds-1 (67 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
qemu1:10.0.2+ds-2 ... 1:11.1.1+ds-1 (56 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 15× in last 7d / 87× 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 100 of 164 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. None are among the latest 100 rows. The 64 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

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

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 October 30, 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.

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