CVE-2021-47536

HIGHNVD 7.87.8
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 7.8 under NVD CVSS v3. EPSS exploit probability: 0.6% (48th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3

Also known asEUVD-2021-34538 (ENISA EUVD)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: 0.6%CVSS: 7.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

net/smc: fix wrong list_del in smc_lgr_cleanup_early

smc_lgr_cleanup_early() meant to delete the link group from the link group list, but it deleted the list head by mistake.

This may cause memory corruption since we didn't remove the real link group from the list and later memseted the link group structure. We got a list corruption panic when testing:

[  231.277259] list_del corruption. prev->next should be ffff8881398a8000, but was 0000000000000000 [  231.278222] ------------[ cut here ]------------ [  231.278726] kernel BUG at lib/list_debug.c:53! [  231.279326] invalid opcode: 0000 [#1] SMP NOPTI [  231.279803] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.10.46+ #435 [  231.280466] Hardware name: Alibaba Cloud ECS, BIOS 8c24b4c 04/01/2014 [  231.281248] Workqueue: events smc_link_down_work [  231.281732] RIP: 0010:__list_del_entry_valid+0x70/0x90 [  231.282258] Code: 4c 60 82 e8 7d cc 6a 00 0f 0b 48 89 fe 48 c7 c7 88 4c 60 82 e8 6c cc 6a 00 0f 0b 48 89 fe 48 c7 c7 c0 4c 60 82 e8 5b cc 6a 00 <0f> 0b 48 89 fe 48 c7 c7 00 4d 60 82 e8 4a cc 6a 00 0f 0b cc cc cc [  231.284146] RSP: 0018:ffffc90000033d58 EFLAGS: 00010292 [  231.284685] RAX: 0000000000000054 RBX: ffff8881398a8000 RCX: 0000000000000000 [  231.285415] RDX: 0000000000000001 RSI: ffff88813bc18040 RDI: ffff88813bc18040 [  231.286141] RBP: ffffffff8305ad40 R08: 0000000000000003 R09: 0000000000000001 [  231.286873] R10: ffffffff82803da0 R11: ffffc90000033b90 R12: 0000000000000001 [  231.287606] R13: 0000000000000000 R14: ffff8881398a8000 R15: 0000000000000003 [  231.288337] FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000 [  231.289160] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [  231.289754] CR2: 0000000000e72058 CR3: 000000010fa96006 CR4: 00000000003706f0 [  231.290485] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [  231.291211] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [  231.291940] Call Trace: [  231.292211]  smc_lgr_terminate_sched+0x53/0xa0 [  231.292677]  smc_switch_conns+0x75/0x6b0 [  231.293085]  ? update_load_avg+0x1a6/0x590 [  231.293517]  ? ttwu_do_wakeup+0x17/0x150 [  231.293907]  ? update_load_avg+0x1a6/0x590 [  231.294317]  ? newidle_balance+0xca/0x3d0 [  231.294716]  smcr_link_down+0x50/0x1a0 [  231.295090]  ? __wake_up_common_lock+0x77/0x90 [  231.295534]  smc_link_down_work+0x46/0x60 [  231.295933]  process_one_work+0x18b/0x350

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.
Exploitation0.6% × 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
0.6%
EPSS %ILE
48th
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.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-03). 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 24, 2024

Last Modified

August 5, 2026

Advisory Details (3)

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

net/smc: fix wrong list_del in smc_lgr_cleanup_early - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/95518fe354d712dca6f431cf2a11b8f63bc9a66c
Web page

net/smc: fix wrong list_del in smc_lgr_cleanup_early - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/789b6cc2a5f9123b9c549b886fdc47c865cfe0ba
Web page

net/smc: fix wrong list_del in smc_lgr_cleanup_early - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/77731fede297a23d26f2d169b4269466b2c82529

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
linux5.10.46-4, 5.10.46-5, 5.10.70-1, 5.10.70-1~bpo10+1
  • every version up to 5.10.84-1: fixed in 5.10.84-1
—
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
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 37× 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 211 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 114 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-04 00:49 UTCEG score recompute
  2. 2026-11-03 16:38 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  3. 2026-11-02 16:38 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  4. 2026-11-01 16:30 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  5. 2026-10-31 16:29 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  6. 2026-10-30 16:30 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  7. 2026-10-29 16:29 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  8. 2026-10-28 16:28 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  9. 2026-10-28 07:32 UTCEG score recompute
  10. 2026-10-27 16:28 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  11. 2026-10-26 16:28 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  12. 2026-10-25 18:18 UTCEG score recompute
  13. 2026-10-25 16:29 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  14. 2026-10-24 16:29 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  15. 2026-10-23 16:28 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  16. 2026-10-22 16:29 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  17. 2026-10-21 16:28 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  18. 2026-10-21 08:31 UTCEG score recompute
  19. 2026-10-20 16:28 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  20. 2026-10-19 16:28 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  21. 2026-10-19 12:25 UTCOSV refresh
  22. 2026-10-18 08:49 UTCEG score recompute
  23. 2026-10-17 16:29 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  24. 2026-10-16 16:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  25. 2026-10-15 16:28 UTCEPSS rescoreEPSS 0.6% · 47th percentile
Show 72 more
  1. 2026-10-14 16:29 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  2. 2026-10-13 16:28 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  3. 2026-10-12 19:05 UTCEG score recompute
  4. 2026-10-12 16:30 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  5. 2026-10-11 23:31 UTCEG score recompute
  6. 2026-10-11 13:44 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  7. 2026-10-10 19:56 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  8. 2026-10-09 20:04 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  9. 2026-10-08 16:40 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  10. 2026-10-07 23:45 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  11. 2026-10-06 15:14 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  12. 2026-10-05 17:40 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  13. 2026-10-04 23:19 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  14. 2026-10-03 14:22 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  15. 2026-10-02 16:23 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  16. 2026-09-30 15:45 UTCEG score recompute
  17. 2026-09-30 15:00 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  18. 2026-09-29 15:15 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  19. 2026-09-28 13:47 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  20. 2026-09-26 19:33 UTCOSV refresh
  21. 2026-09-26 15:54 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  22. 2026-09-26 00:21 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  23. 2026-09-24 14:00 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  24. 2026-09-23 13:45 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  25. 2026-09-22 14:44 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  26. 2026-09-21 20:28 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  27. 2026-09-20 20:13 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  28. 2026-09-19 15:38 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  29. 2026-09-18 19:24 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  30. 2026-09-17 19:23 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  31. 2026-09-16 14:05 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  32. 2026-09-15 03:06 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  33. 2026-09-12 14:57 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  34. 2026-09-11 14:49 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  35. 2026-09-11 09:33 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  36. 2026-09-08 21:57 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  37. 2026-09-07 15:58 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  38. 2026-09-07 05:18 UTCOSV refresh
  39. 2026-09-06 13:45 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  40. 2026-09-05 15:25 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  41. 2026-09-04 13:57 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  42. 2026-09-04 05:03 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  43. 2026-09-02 14:09 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  44. 2026-09-01 13:51 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  45. 2026-08-30 19:14 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  46. 2026-08-30 01:19 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  47. 2026-08-28 21:38 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  48. 2026-08-27 14:22 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  49. 2026-08-26 14:43 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  50. 2026-08-25 13:46 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  51. 2026-08-24 14:13 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  52. 2026-08-21 23:46 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  53. 2026-08-20 22:52 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  54. 2026-08-20 15:01 UTCOSV refresh
  55. 2026-08-19 17:01 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  56. 2026-08-18 13:45 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  57. 2026-08-17 13:44 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  58. 2026-08-16 14:53 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  59. 2026-08-16 02:11 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  60. 2026-08-15 01:27 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  61. 2026-08-13 21:57 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  62. 2026-08-12 13:48 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  63. 2026-08-11 13:38 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  64. 2026-08-09 13:44 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  65. 2026-08-08 16:34 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  66. 2026-08-07 16:24 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  67. 2026-08-06 13:44 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  68. 2026-08-05 19:15 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  69. 2026-08-05 09:39 UTCEG score recompute
  70. 2026-08-04 15:06 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  71. 2026-08-04 12:10 UTCEG score recompute
  72. 2026-08-04 10:34 UTCEPSS rescoreEPSS 0.2% · 14th percentile

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-47536?
CVE-2021-47536 is a high-severity vulnerability; its CVE record was published on May 24, 2024. In the Linux kernel, the following vulnerability has been resolved: net/smc: fix wrong list_del in smc_lgr_cleanup_early smc_lgr_cleanup_early() meant to delete the link group from the link group list, but it deleted the list head by mistake. This may cause memory corruption since we didn't remove…
When was the CVE record for CVE-2021-47536 published?
The CVE record for CVE-2021-47536 was published on May 24, 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-2021-47536 actively exploited?
CVE-2021-47536 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (48th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-47536?
CVE-2021-47536 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2021-47536?
A fix for CVE-2021-47536 is available: update to the fixed version the vendor names in its advisory.

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