CVE-2021-47261

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 2024-05-21. 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 — 3 sources updated this week

Also known asEUVD-2021-34266 (ENISA EUVD) · GHSA-2v93-g9j3-9q9h (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: 0.2%CVSS: 7.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

IB/mlx5: Fix initializing CQ fragments buffer

The function init_cq_frag_buf() can be called to initialize the current CQ fragments buffer cq->buf, or the temporary cq->resize_buf that is filled during CQ resize operation.

However, the offending commit started to use function get_cqe() for getting the CQEs, the issue with this change is that get_cqe() always returns CQEs from cq->buf, which leads us to initialize the wrong buffer, and in case of enlarging the CQ we try to access elements beyond the size of the current cq->buf and eventually hit a kernel panic.

[exception RIP: init_cq_frag_buf+103] [ffff9f799ddcbcd8] mlx5_ib_resize_cq at ffffffffc0835d60 [mlx5_ib] [ffff9f799ddcbdb0] ib_resize_cq at ffffffffc05270df [ib_core] [ffff9f799ddcbdc0] llt_rdma_setup_qp at ffffffffc0a6a712 [llt] [ffff9f799ddcbe10] llt_rdma_cc_event_action at ffffffffc0a6b411 [llt] [ffff9f799ddcbe98] llt_rdma_client_conn_thread at ffffffffc0a6bb75 [llt] [ffff9f799ddcbec8] kthread at ffffffffa66c5da1 [ffff9f799ddcbf50] ret_from_fork_nospec_begin at ffffffffa6d95ddd

Fix it by getting the needed CQE by calling mlx5_frag_buf_get_wqe() that takes the correct source buffer as a parameter.

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.
Exploitation0.2% × 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
0.2%
EPSS %ILE
14th
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
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). 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

May 21, 2024

Last Modified

August 5, 2026

Advisory Details (5)

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

IB/mlx5: Fix initializing CQ fragments buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e3ecd9c09fcc10cf6b2bc67e2990c397c40a8c26
Web page

IB/mlx5: Fix initializing CQ fragments buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/91f7fdc4cc10542ca1045c06aad23365f0d067e0
Web page

IB/mlx5: Fix initializing CQ fragments buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3e670c54eda238cb8a1ea93538a79ae89285c1c4
Web page

IB/mlx5: Fix initializing CQ fragments buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2ba0aa2feebda680ecfc3c552e867cf4d1b05a3a
Web page

IB/mlx5: Fix initializing CQ fragments buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1ec2dcd680c71d0d36fa25638b327a468babd5c9

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 9× in last 7d / 39× 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 213 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 116 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 0.2% · 14th percentile
  2. 2026-11-01 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  3. 2026-10-31 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  4. 2026-10-30 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  5. 2026-10-29 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  6. 2026-10-28 16:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  7. 2026-10-28 15:05 UTCEG score recompute
  8. 2026-10-28 15:05 UTCGHSA enrichmentGHSA-2v93-g9j3-9q9h · GitHub severity HIGH · GitHub CVSS 7.8
  9. 2026-10-27 16:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  10. 2026-10-26 16:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  11. 2026-10-25 18:18 UTCEG score recompute
  12. 2026-10-25 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  13. 2026-10-24 16:29 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  14. 2026-10-23 16:28 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  15. 2026-10-22 16:29 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  16. 2026-10-21 16:28 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  17. 2026-10-21 08:34 UTCEG score recompute
  18. 2026-10-21 08:34 UTCGHSA enrichmentGHSA-2v93-g9j3-9q9h · GitHub severity HIGH · GitHub CVSS 7.8
  19. 2026-10-20 16:28 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  20. 2026-10-19 16:28 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  21. 2026-10-19 13:25 UTCOSV refresh
  22. 2026-10-18 16:28 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  23. 2026-10-18 08:49 UTCEG score recompute
  24. 2026-10-17 16:29 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  25. 2026-10-16 16:34 UTCEPSS rescoreEPSS 0.2% · 13th percentile
Show 72 more
  1. 2026-10-15 16:28 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  2. 2026-10-14 16:29 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  3. 2026-10-13 16:28 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  4. 2026-10-12 19:05 UTCEG score recompute
  5. 2026-10-12 16:30 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  6. 2026-10-11 23:31 UTCEG score recompute
  7. 2026-10-11 13:44 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  8. 2026-10-10 19:56 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  9. 2026-10-09 20:04 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  10. 2026-10-08 16:40 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  11. 2026-10-07 23:45 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  12. 2026-10-06 15:14 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  13. 2026-10-05 17:40 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  14. 2026-10-04 23:19 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  15. 2026-10-03 14:22 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  16. 2026-10-02 16:23 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  17. 2026-09-30 15:45 UTCEG score recompute
  18. 2026-09-30 15:00 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  19. 2026-09-29 15:15 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  20. 2026-09-28 13:47 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  21. 2026-09-26 20:03 UTCOSV refresh
  22. 2026-09-26 15:54 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  23. 2026-09-26 00:21 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  24. 2026-09-24 14:00 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  25. 2026-09-23 13:45 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  26. 2026-09-22 14:44 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  27. 2026-09-21 20:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  28. 2026-09-20 20:13 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  29. 2026-09-19 15:38 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  30. 2026-09-18 19:24 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  31. 2026-09-17 19:23 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  32. 2026-09-16 14:05 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  33. 2026-09-15 03:06 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  34. 2026-09-12 14:57 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  35. 2026-09-11 14:49 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  36. 2026-09-11 09:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  37. 2026-09-08 21:57 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  38. 2026-09-07 15:58 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  39. 2026-09-07 05:47 UTCOSV refresh
  40. 2026-09-06 13:45 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  41. 2026-09-05 15:25 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  42. 2026-09-04 13:57 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  43. 2026-09-04 05:03 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  44. 2026-09-02 14:09 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  45. 2026-09-01 13:51 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  46. 2026-08-30 19:14 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  47. 2026-08-30 01:19 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  48. 2026-08-28 21:38 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  49. 2026-08-27 14:22 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  50. 2026-08-26 14:43 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  51. 2026-08-24 14:13 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  52. 2026-08-21 23:46 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  53. 2026-08-20 22:52 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  54. 2026-08-20 15:31 UTCOSV refresh
  55. 2026-08-19 17:01 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  56. 2026-08-18 13:45 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  57. 2026-08-17 13:44 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  58. 2026-08-16 14:53 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  59. 2026-08-16 02:11 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  60. 2026-08-15 01:27 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  61. 2026-08-13 21:57 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  62. 2026-08-12 13:48 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  63. 2026-08-11 13:38 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  64. 2026-08-09 13:44 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  65. 2026-08-07 16:24 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  66. 2026-08-05 19:15 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  67. 2026-08-05 09:41 UTCEG score recompute
  68. 2026-08-05 09:40 UTCGHSA enrichmentGHSA-2v93-g9j3-9q9h · GitHub severity HIGH · GitHub CVSS 7.8
  69. 2026-08-04 15:06 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  70. 2026-08-04 12:13 UTCEG score recompute
  71. 2026-08-04 12:12 UTCGHSA enrichmentGHSA-2v93-g9j3-9q9h · GitHub severity HIGH · GitHub CVSS 7.8
  72. 2026-08-04 10:34 UTCEPSS rescoreEPSS 0.2% · 14th percentile

Frequently asked(5)

What is CVE-2021-47261?
CVE-2021-47261 is a high-severity vulnerability; its CVE record was published on May 21, 2024. In the Linux kernel, the following vulnerability has been resolved: IB/mlx5: Fix initializing CQ fragments buffer The function init_cq_frag_buf() can be called to initialize the current CQ fragments buffer cq->buf, or the temporary cq->resize_buf that is filled during CQ resize operation. However,…
When was the CVE record for CVE-2021-47261 published?
The CVE record for CVE-2021-47261 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-2021-47261 actively exploited?
CVE-2021-47261 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (14th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-47261?
CVE-2021-47261 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2021-47261?
A fix for CVE-2021-47261 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-47261

Explore →

Is Your Infrastructure Affected by CVE-2021-47261?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.