CVE-2021-47092

MEDIUMNVD 5.55.5
EchelonGraph scoreMEDIUM confidence

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

Score 5.5 from GitHub Security Advisory published 2024-03-04. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
5.5EG
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: 0.3%CVSS: 5.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

KVM: VMX: Always clear vmx->fail on emulation_required

Revert a relatively recent change that set vmx->fail if the vCPU is in L2 and emulation_required is true, as that behavior is completely bogus. Setting vmx->fail and synthesizing a VM-Exit is contradictory and wrong:

(a) it's impossible to have both a VM-Fail and VM-Exit (b) vmcs.EXIT_REASON is not modified on VM-Fail (c) emulation_required refers to guest state and guest state checks are always VM-Exits, not VM-Fails.

For KVM specifically, emulation_required is handled before nested exits in __vmx_handle_exit(), thus setting vmx->fail has no immediate effect, i.e. KVM calls into handle_invalid_guest_state() and vmx->fail is ignored. Setting vmx->fail can ultimately result in a WARN in nested_vmx_vmexit() firing when tearing down the VM as KVM never expects vmx->fail to be set when L2 is active, KVM always reflects those errors into L1.

------------[ cut here ]------------ WARNING: CPU: 0 PID: 21158 at arch/x86/kvm/vmx/nested.c:4548 nested_vmx_vmexit+0x16bd/0x17e0 arch/x86/kvm/vmx/nested.c:4547 Modules linked in: CPU: 0 PID: 21158 Comm: syz-executor.1 Not tainted 5.16.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:nested_vmx_vmexit+0x16bd/0x17e0 arch/x86/kvm/vmx/nested.c:4547 Code: <0f> 0b e9 2e f8 ff ff e8 57 b3 5d 00 0f 0b e9 00 f1 ff ff 89 e9 80 Call Trace: vmx_leave_nested arch/x86/kvm/vmx/nested.c:6220 [inline] nested_vmx_free_vcpu+0x83/0xc0 arch/x86/kvm/vmx/nested.c:330 vmx_free_vcpu+0x11f/0x2a0 arch/x86/kvm/vmx/vmx.c:6799 kvm_arch_vcpu_destroy+0x6b/0x240 arch/x86/kvm/x86.c:10989 kvm_vcpu_destroy+0x29/0x90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:441 kvm_free_vcpus arch/x86/kvm/x86.c:11426 [inline] kvm_arch_destroy_vm+0x3ef/0x6b0 arch/x86/kvm/x86.c:11545 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1189 [inline] kvm_put_kvm+0x751/0xe40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1220 kvm_vcpu_release+0x53/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3489 __fput+0x3fc/0x870 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0x705/0x24f0 kernel/exit.c:832 do_group_exit+0x168/0x2d0 kernel/exit.c:929 get_signal+0x1740/0x2120 kernel/signal.c:2852 arch_do_signal_or_restart+0x9c/0x730 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300 do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae

CVSS v3
5.5
EG Score
5.5MEDIUMmedium confidence
EG Risk
25
EG Risk 25/100

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)
Severity55% × 45%
Impact severity (EG Severity): CVSS 5.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.3% × 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
0.3%
EPSS %ILE
20th
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 (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.

EG Severity
5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). 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 4, 2024

Last Modified

February 14, 2025

References (2)

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.15.15-1: fixed in 5.15.15-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.15.15-1: fixed in 5.15.15-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.15.15-1: fixed in 5.15.15-1
—

Data Freshness Timeline

(refreshed 8× in last 7d / 33× 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 95 of 189 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. 5 repeat rows among the latest 100 are merged into the row they repeat. The 94 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

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

Frequently asked(5)

What is CVE-2021-47092?
CVE-2021-47092 is a medium-severity vulnerability; its CVE record was published on March 4, 2024. In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Always clear vmx->fail on emulation_required Revert a relatively recent change that set vmx->fail if the vCPU is in L2 and emulation_required is true, as that behavior is completely bogus. Setting vmx->fail and…
When was the CVE record for CVE-2021-47092 published?
The CVE record for CVE-2021-47092 was published on March 4, 2024. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of February 14, 2025; the record at its source may have been updated since.
Is CVE-2021-47092 actively exploited?
CVE-2021-47092 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (20th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-47092?
CVE-2021-47092 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2021-47092?
A fix for CVE-2021-47092 is available: update to the fixed version the vendor names in its advisory.

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