CVE-2021-47274

CRITICALNVD 9.89.8
EchelonGraph scoreMEDIUM confidence

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

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2024-05-21. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this week

Also known asEUVD-2021-34279 (ENISA EUVD) · GHSA-px85-vjfw-cm92 (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
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).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.8%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

tracing: Correct the length check which causes memory corruption

We've suffered from severe kernel crashes due to memory corruption on our production environment, like,

Call Trace: [1640542.554277] general protection fault: 0000 [#1] SMP PTI [1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: loaded Tainted:G [1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190 [1640542.559074] RSP: 0018:ffffb16faa597df8 EFLAGS: 00010286 [1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX: 0000000006e931bf [1640542.560323] RDX: 0000000006e931be RSI: 0000000000400200 RDI: ffff9a45ff004300 [1640542.560996] RBP: 0000000000400200 R08: 0000000000023420 R09: 0000000000000000 [1640542.561670] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff9a20608d [1640542.562366] R13: ffff9a45ff004300 R14: ffff9a45ff004300 R15: 696c662f65636976 [1640542.563128] FS: 00007f45d7c6f740(0000) GS:ffff9a45ff840000(0000) knlGS:0000000000000000 [1640542.563937] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1640542.564557] CR2: 00007f45d71311a0 CR3: 000000189d63e004 CR4: 00000000003606e0 [1640542.565279] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [1640542.566069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [1640542.566742] Call Trace: [1640542.567009] anon_vma_clone+0x5d/0x170 [1640542.567417] __split_vma+0x91/0x1a0 [1640542.567777] do_munmap+0x2c6/0x320 [1640542.568128] vm_munmap+0x54/0x70 [1640542.569990] __x64_sys_munmap+0x22/0x30 [1640542.572005] do_syscall_64+0x5b/0x1b0 [1640542.573724] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [1640542.575642] RIP: 0033:0x7f45d6e61e27

James Wang has reproduced it stably on the latest 4.19 LTS. After some debugging, we finally proved that it's due to ftrace buffer out-of-bound access using a debug tool as follows: [ 86.775200] BUG: Out-of-bounds write at addr 0xffff88aefe8b7000 [ 86.780806] no_context+0xdf/0x3c0 [ 86.784327] __do_page_fault+0x252/0x470 [ 86.788367] do_page_fault+0x32/0x140 [ 86.792145] page_fault+0x1e/0x30 [ 86.795576] strncpy_from_unsafe+0x66/0xb0 [ 86.799789] fetch_memory_string+0x25/0x40 [ 86.804002] fetch_deref_string+0x51/0x60 [ 86.808134] kprobe_trace_func+0x32d/0x3a0 [ 86.812347] kprobe_dispatcher+0x45/0x50 [ 86.816385] kprobe_ftrace_handler+0x90/0xf0 [ 86.820779] ftrace_ops_assist_func+0xa1/0x140 [ 86.825340] 0xffffffffc00750bf [ 86.828603] do_sys_open+0x5/0x1f0 [ 86.832124] do_syscall_64+0x5b/0x1b0 [ 86.835900] entry_SYSCALL_64_after_hwframe+0x44/0xa9

commit b220c049d519 ("tracing: Check length before giving out the filter buffer") adds length check to protect trace data overflow introduced in 0fc1b09ff1ff, seems that this fix can't prevent overflow entirely, the length check should also take the sizeof entry->array[0] into account, since this array[0] is filled the length of trace data and occupy addtional space and risk overflow.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
59
EG Risk 59/100

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)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.8% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (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
0.8%
EPSS %ILE
55th
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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.8% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). 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 or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days 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 or medium mission impact; Attend at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable yes (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)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

May 21, 2024

Last Modified

August 5, 2026

Advisory Details (7)

Auto-updated Oct 31, 2026
Patch available.
Web page

tracing: Correct the length check which causes memory corruption - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3e08a9f9760f4a70d633c328a76408e62d6f80a3
Web page

tracing: Correct the length check which causes memory corruption - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b16a249eca2230c2cd66fa1d4b94743bd9b6ef92
Web page

tracing: Correct the length check which causes memory corruption - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/43c32c22254b9328d7abb1c2b0f689dc67838e60
Web page

tracing: Correct the length check which causes memory corruption - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d63f00ec908b3be635ead5d6029cc94246e1f38d
Web page

tracing: Correct the length check which causes memory corruption - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/31ceae385556c37e4d286cb6378696448f566883
Web page

tracing: Correct the length check which causes memory corruption - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2d598902799886d67947406f26ee8e5fd2ca097f
Web page

tracing: Correct the length check which causes memory corruption - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/edcce01e0e50840a9aa6a70baed21477bdd2c9f9

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.10.46-1: fixed in 5.10.46-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.10.46-1: fixed in 5.10.46-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.10.46-1: fixed in 5.10.46-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.10.46-1: fixed in 5.10.46-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 22× in last 7d / 72× 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 97 of 248 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. 3 repeat rows among the latest 100 are merged into the row they repeat. The 151 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:38 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  2. 2026-11-02 05:44 UTCEG score recompute
  3. 2026-11-02 05:44 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-11-01 16:30 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  5. 2026-11-01 04:46 UTCEG score recompute
  6. 2026-11-01 04:46 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-10-31 16:29 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  8. 2026-10-31 03:48 UTCEG score recompute
  9. 2026-10-31 03:48 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  10. 2026-10-30 16:30 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  11. 2026-10-30 02:50 UTCEG score recompute
  12. 2026-10-30 02:50 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-29 16:29 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  14. 2026-10-29 01:52 UTCEG score recompute
  15. 2026-10-29 01:51 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  16. 2026-10-28 16:28 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  17. 2026-10-28 00:52 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-28 00:52 UTCEG score recompute
  19. 2026-10-28 00:52 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-10-27 16:28 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  21. 2026-10-26 23:51 UTCEG score recompute
  22. 2026-10-26 23:51 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  23. 2026-10-26 16:28 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  24. 2026-10-25 19:18 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-10-25 18:18 UTCEG score recompute
Show 72 more
  1. 2026-10-25 16:29 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  2. 2026-10-24 18:16 UTCEG score recompute
  3. 2026-10-24 18:16 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-10-24 16:29 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  5. 2026-10-23 17:18 UTCEG score recompute
  6. 2026-10-23 17:18 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-10-23 16:28 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  8. 2026-10-22 16:29 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  9. 2026-10-22 16:20 UTCEG score recompute
  10. 2026-10-22 16:20 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  11. 2026-10-21 16:28 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  12. 2026-10-21 14:38 UTCEG score recompute
  13. 2026-10-21 14:38 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  14. 2026-10-20 16:28 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  15. 2026-10-20 13:41 UTCEG score recompute
  16. 2026-10-20 13:41 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-10-19 16:28 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  18. 2026-10-19 12:42 UTCEG score recompute
  19. 2026-10-19 12:42 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-10-18 16:28 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  21. 2026-10-18 11:05 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-10-18 08:49 UTCEG score recompute
  23. 2026-10-17 16:29 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  24. 2026-10-17 09:45 UTCEG score recompute
  25. 2026-10-17 09:45 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  26. 2026-10-16 16:34 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  27. 2026-10-16 08:48 UTCEG score recompute
  28. 2026-10-16 08:47 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  29. 2026-10-15 16:28 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  30. 2026-10-15 07:49 UTCEG score recompute
  31. 2026-10-15 07:49 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  32. 2026-10-14 16:29 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  33. 2026-10-14 03:48 UTCEG score recompute
  34. 2026-10-14 03:48 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  35. 2026-10-13 16:28 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  36. 2026-10-12 23:43 UTCGHSA enrichmentGHSA-px85-vjfw-cm92 · GitHub severity CRITICAL · GitHub CVSS 9.8
  37. 2026-10-12 19:05 UTCEG score recompute
  38. 2026-10-12 16:30 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  39. 2026-10-11 23:31 UTCEG score recompute
  40. 2026-10-11 13:44 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  41. 2026-10-10 19:56 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  42. 2026-10-09 20:04 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  43. 2026-10-08 16:40 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  44. 2026-10-07 23:45 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  45. 2026-10-06 15:14 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  46. 2026-10-05 17:40 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  47. 2026-10-04 23:19 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  48. 2026-10-03 14:22 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  49. 2026-10-02 16:23 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  50. 2026-09-30 15:45 UTCEG score recompute
  51. 2026-09-30 15:00 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  52. 2026-09-29 15:15 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  53. 2026-09-28 13:47 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  54. 2026-09-26 20:33 UTCOSV refresh
  55. 2026-09-26 15:54 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  56. 2026-09-26 00:21 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  57. 2026-09-24 14:00 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  58. 2026-09-23 13:45 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  59. 2026-09-22 14:44 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  60. 2026-09-21 20:28 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  61. 2026-09-20 20:13 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  62. 2026-09-19 15:38 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  63. 2026-09-18 19:24 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  64. 2026-09-17 19:23 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  65. 2026-09-16 14:05 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  66. 2026-09-15 03:06 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  67. 2026-09-12 14:57 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  68. 2026-09-11 14:49 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  69. 2026-09-11 09:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  70. 2026-09-08 21:57 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  71. 2026-09-07 15:58 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  72. 2026-09-07 05:48 UTCOSV refresh

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Frequently asked(5)

What is CVE-2021-47274?
CVE-2021-47274 is a critical-severity vulnerability; its CVE record was published on May 21, 2024. In the Linux kernel, the following vulnerability has been resolved: tracing: Correct the length check which causes memory corruption We've suffered from severe kernel crashes due to memory corruption on our production environment, like, Call Trace: [1640542.554277] general protection fault: 0000…
When was the CVE record for CVE-2021-47274 published?
The CVE record for CVE-2021-47274 was published on May 21, 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 August 5, 2026; the record at its source may have been updated since.
Is CVE-2021-47274 actively exploited?
CVE-2021-47274 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.8% probability of exploitation in the next 30 days (55th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-47274?
CVE-2021-47274 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2021-47274?
A fix for CVE-2021-47274 is available: update to the fixed version the vendor names in its advisory.

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