CVE-2021-47040

HIGHNVD 7.87.8
EchelonGraph scoreMEDIUM confidence

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

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2024-02-28. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this week

Also known asEUVD-2021-33688 (ENISA EUVD) · GHSA-phvq-9637-vp75 (GitHub Security Advisories)Source: ENISA EUVD

7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 7.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

io_uring: fix overflows checks in provide buffers

Colin reported before possible overflow and sign extension problems in io_provide_buffers_prep(). As Linus pointed out previous attempt did nothing useful, see d81269fecb8ce ("io_uring: fix provide_buffers sign extension").

Do that with help of check__overflow helpers. And fix struct io_provide_buf::len type, as it doesn't make much sense to keep it signed.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
35
EG Risk 35/100

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)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 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
18th
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 (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.

EG Severity
7.8 HIGHCVSS-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 2026-10-28). 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, and whom BOD 26-04 binds: 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.

The score's inputs: 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

February 28, 2024

Last Modified

August 5, 2026

Advisory Details (4)

Auto-updated Aug 4, 2026
Patch available.
Web page

io_uring: fix overflows checks in provide buffers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/cbbc13b115b8f18e0a714d89f87fbdc499acfe2d
Web page

io_uring: fix overflows checks in provide buffers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/84b8c266c4bfe9ed5128e13253c388deb74b1b03
Web page

io_uring: fix overflows checks in provide buffers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/51bf90901952aaac564bbdb36b2b503050c53dd9
Web page

io_uring: fix overflows checks in provide buffers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/38134ada0ceea3e848fe993263c0ff6207fd46e7

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.10.38-1: fixed in 5.10.38-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.10.38-1: fixed in 5.10.38-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.10.38-1: fixed in 5.10.38-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.10.38-1: fixed in 5.10.38-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 40× 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 214 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 117 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 0.3% · 18th percentile
  2. 2026-11-01 16:30 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  3. 2026-10-31 16:29 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  4. 2026-10-30 16:30 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  5. 2026-10-29 16:29 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  6. 2026-10-29 04:03 UTCEG score recompute
  7. 2026-10-29 04:03 UTCGHSA enrichmentGHSA-phvq-9637-vp75 · GitHub severity HIGH · GitHub CVSS 7.8
  8. 2026-10-29 02:55 UTCOSV refresh
  9. 2026-10-28 16:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  10. 2026-10-27 16:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  11. 2026-10-26 16:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  12. 2026-10-25 18:18 UTCEG score recompute
  13. 2026-10-25 16:29 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  14. 2026-10-24 16:29 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  15. 2026-10-23 16:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  16. 2026-10-22 16:29 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  17. 2026-10-21 16:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  18. 2026-10-21 08:35 UTCEG score recompute
  19. 2026-10-21 08:35 UTCGHSA enrichmentGHSA-phvq-9637-vp75 · GitHub severity HIGH · GitHub CVSS 7.8
  20. 2026-10-20 16:28 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  21. 2026-10-19 16:28 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  22. 2026-10-19 13:25 UTCOSV refresh
  23. 2026-10-18 16:28 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  24. 2026-10-18 08:50 UTCEG score recompute
  25. 2026-10-17 16:29 UTCEPSS rescoreEPSS 0.3% · 16th percentile
Show 72 more
  1. 2026-10-16 16:34 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  2. 2026-10-15 16:28 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  3. 2026-10-14 16:29 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  4. 2026-10-13 16:28 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  5. 2026-10-12 19:05 UTCEG score recompute
  6. 2026-10-12 16:30 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  7. 2026-10-11 23:31 UTCEG score recompute
  8. 2026-10-11 13:44 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  9. 2026-10-10 19:56 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  10. 2026-10-09 20:04 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  11. 2026-10-08 16:40 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  12. 2026-10-07 23:45 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  13. 2026-10-06 15:14 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  14. 2026-10-05 17:40 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  15. 2026-10-04 23:19 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  16. 2026-10-03 14:22 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  17. 2026-10-02 16:23 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  18. 2026-09-30 15:45 UTCEG score recompute
  19. 2026-09-30 15:00 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  20. 2026-09-29 15:15 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  21. 2026-09-28 13:47 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  22. 2026-09-26 20:33 UTCOSV refresh
  23. 2026-09-26 15:54 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  24. 2026-09-26 00:21 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  25. 2026-09-24 14:00 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  26. 2026-09-23 13:45 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  27. 2026-09-22 14:44 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  28. 2026-09-21 20:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  29. 2026-09-20 20:13 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  30. 2026-09-19 15:38 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  31. 2026-09-18 19:24 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  32. 2026-09-17 19:23 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  33. 2026-09-16 14:05 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  34. 2026-09-15 03:06 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  35. 2026-09-12 14:57 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  36. 2026-09-11 14:49 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  37. 2026-09-11 09:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  38. 2026-09-08 21:57 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  39. 2026-09-07 15:58 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  40. 2026-09-07 05:48 UTCOSV refresh
  41. 2026-09-06 13:45 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  42. 2026-09-05 15:25 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  43. 2026-09-04 13:57 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  44. 2026-09-04 05:03 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  45. 2026-09-02 14:09 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  46. 2026-09-01 13:51 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  47. 2026-08-30 19:14 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  48. 2026-08-30 01:19 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  49. 2026-08-28 21:38 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  50. 2026-08-26 14:43 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  51. 2026-08-25 13:46 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  52. 2026-08-24 14:13 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  53. 2026-08-21 23:46 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  54. 2026-08-20 22:52 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  55. 2026-08-20 15:31 UTCOSV refresh
  56. 2026-08-19 17:01 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  57. 2026-08-18 13:45 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  58. 2026-08-17 13:44 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  59. 2026-08-16 14:53 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  60. 2026-08-16 02:11 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  61. 2026-08-15 01:27 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  62. 2026-08-13 21:57 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  63. 2026-08-12 13:48 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  64. 2026-08-11 13:38 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  65. 2026-08-09 13:44 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  66. 2026-08-08 16:34 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  67. 2026-08-07 16:24 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  68. 2026-08-06 13:44 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  69. 2026-08-05 19:15 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  70. 2026-08-05 09:44 UTCEG score recompute
  71. 2026-08-05 09:44 UTCGHSA enrichmentGHSA-phvq-9637-vp75 · GitHub severity HIGH · GitHub CVSS 7.8
  72. 2026-08-04 15:06 UTCEPSS rescoreEPSS 0.3% · 17th percentile

Frequently asked(5)

What is CVE-2021-47040?
CVE-2021-47040 is a high-severity vulnerability; its CVE record was published on February 28, 2024. In the Linux kernel, the following vulnerability has been resolved: io_uring: fix overflows checks in provide buffers Colin reported before possible overflow and sign extension problems in io_provide_buffers_prep(). As Linus pointed out previous attempt did nothing useful, see d81269fecb8ce…
When was the CVE record for CVE-2021-47040 published?
The CVE record for CVE-2021-47040 was published on February 28, 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-2021-47040 actively exploited?
CVE-2021-47040 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (18th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-47040?
CVE-2021-47040 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2021-47040?
A fix for CVE-2021-47040 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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