CVE-2021-47254

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 — 4 sources updated this week

Also known asEUVD-2021-33902 (ENISA EUVD) · GHSA-g3v4-6rhh-7539 (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:

gfs2: Fix use-after-free in gfs2_glock_shrink_scan

The GLF_LRU flag is checked under lru_lock in gfs2_glock_remove_from_lru() to remove the glock from the lru list in __gfs2_glock_put().

On the shrink scan path, the same flag is cleared under lru_lock but because of cond_resched_lock(&lru_lock) in gfs2_dispose_glock_lru(), progress on the put side can be made without deleting the glock from the lru list.

Keep GLF_LRU across the race window opened by cond_resched_lock(&lru_lock) to ensure correct behavior on both sides - clear GLF_LRU after list_del under lru_lock.

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
15th
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 (8)

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

gfs2: Fix use-after-free in gfs2_glock_shrink_scan - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/094bf5670e762afa243d2c41a5c4ab71c7447bf4
Web page

gfs2: Fix use-after-free in gfs2_glock_shrink_scan - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0364742decb0f02bc183404868b82896f7992595
Web page

gfs2: Fix use-after-free in gfs2_glock_shrink_scan - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e87ef30fe73e7e10d2c85bdcc778dcec24dca553
Web page

gfs2: Fix use-after-free in gfs2_glock_shrink_scan - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a61156314b66456ab6a291ed5deba1ebd002ab3c
Web page

gfs2: Fix use-after-free in gfs2_glock_shrink_scan - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/92869945cc5b78ee8a1ef90336fe070893e3458a
Web page

gfs2: Fix use-after-free in gfs2_glock_shrink_scan - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/86fd5b27db743a0ce0cc245e3a34813b2aa6ec1d
Web page

gfs2: Fix use-after-free in gfs2_glock_shrink_scan - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/38ce329534500bf4ae71f81df6a37a406cf187b4
Web page

gfs2: Fix use-after-free in gfs2_glock_shrink_scan - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1ab19c5de4c537ec0d9b21020395a5b5a6c059b2

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulinux-virtual-lts-xenial (4.4.0.279.285) @ xenial2026-10-28ubuntu
ubuntulinux-tools-fips (4.4.0.1123.124) @ xenial2026-10-28ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

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.

All Vendor Advisories

(2)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 9× 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 217 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 120 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% · 15th percentile
  2. 2026-11-01 16:30 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  3. 2026-10-30 16:30 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  4. 2026-10-29 16:29 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  5. 2026-10-28 16:28 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  6. 2026-10-28 12:45 UTCEG score recompute
  7. 2026-10-28 12:45 UTCVendor advisory
  8. 2026-10-28 12:45 UTCGHSA enrichmentGHSA-g3v4-6rhh-7539 · GitHub severity HIGH · GitHub CVSS 7.8
  9. 2026-10-27 16:28 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  10. 2026-10-26 16:28 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  11. 2026-10-25 18:18 UTCEG score recompute
  12. 2026-10-25 16:29 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  13. 2026-10-24 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  14. 2026-10-23 16:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  15. 2026-10-22 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  16. 2026-10-21 16:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  17. 2026-10-21 08:34 UTCEG score recompute
  18. 2026-10-21 08:34 UTCVendor advisory
  19. 2026-10-21 08:34 UTCGHSA enrichmentGHSA-g3v4-6rhh-7539 · GitHub severity HIGH · GitHub CVSS 7.8
  20. 2026-10-20 16:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  21. 2026-10-19 16:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  22. 2026-10-19 12:55 UTCOSV refresh
  23. 2026-10-18 16:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  24. 2026-10-18 08:49 UTCEG score recompute
  25. 2026-10-17 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
Show 72 more
  1. 2026-10-16 16:34 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  2. 2026-10-15 16:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  3. 2026-10-14 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  4. 2026-10-13 16:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  5. 2026-10-12 19:05 UTCEG score recompute
  6. 2026-10-12 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  7. 2026-10-11 23:31 UTCEG score recompute
  8. 2026-10-11 13:44 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  9. 2026-10-10 19:56 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  10. 2026-10-09 20:04 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  11. 2026-10-08 16:40 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  12. 2026-10-07 23:45 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  13. 2026-10-06 15:14 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  14. 2026-10-05 17:40 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  15. 2026-10-04 23:19 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  16. 2026-10-03 14:22 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  17. 2026-10-02 16:23 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  18. 2026-09-30 15:45 UTCEG score recompute
  19. 2026-09-30 15:00 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  20. 2026-09-29 15:15 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  21. 2026-09-28 13:47 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  22. 2026-09-26 20:03 UTCOSV refresh
  23. 2026-09-26 15:54 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  24. 2026-09-26 00:21 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  25. 2026-09-24 14:00 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  26. 2026-09-23 13:45 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  27. 2026-09-22 14:44 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  28. 2026-09-21 20:28 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  29. 2026-09-20 20:13 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  30. 2026-09-19 15:38 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  31. 2026-09-18 19:24 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  32. 2026-09-17 19:23 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  33. 2026-09-16 14:05 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  34. 2026-09-15 03:06 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  35. 2026-09-12 14:57 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  36. 2026-09-11 14:49 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  37. 2026-09-11 09:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  38. 2026-09-08 21:57 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  39. 2026-09-07 15:58 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  40. 2026-09-07 05:48 UTCOSV refresh
  41. 2026-09-06 13:45 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  42. 2026-09-05 15:25 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  43. 2026-09-04 13:57 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  44. 2026-09-04 05:03 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  45. 2026-09-02 14:09 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  46. 2026-09-01 13:51 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  47. 2026-08-30 19:14 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  48. 2026-08-30 01:19 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  49. 2026-08-28 21:38 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  50. 2026-08-27 14:22 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  51. 2026-08-26 14:43 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  52. 2026-08-25 13:46 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  53. 2026-08-24 14:13 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  54. 2026-08-21 23:46 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  55. 2026-08-20 22:52 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  56. 2026-08-20 15:31 UTCOSV refresh
  57. 2026-08-19 17:01 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  58. 2026-08-18 13:45 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  59. 2026-08-17 13:44 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  60. 2026-08-16 14:53 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  61. 2026-08-16 02:11 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  62. 2026-08-15 01:27 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  63. 2026-08-13 21:57 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  64. 2026-08-12 13:48 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  65. 2026-08-11 13:38 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  66. 2026-08-09 13:44 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  67. 2026-08-08 16:34 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  68. 2026-08-07 16:24 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  69. 2026-08-05 19:15 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  70. 2026-08-05 09:41 UTCEG score recompute
  71. 2026-08-05 09:41 UTCGHSA enrichmentGHSA-g3v4-6rhh-7539 · GitHub severity HIGH · GitHub CVSS 7.8
  72. 2026-08-04 15:06 UTCEPSS rescoreEPSS 0.2% · 15th percentile

Frequently asked(5)

What is CVE-2021-47254?
CVE-2021-47254 is a high-severity vulnerability; its CVE record was published on May 21, 2024. In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix use-after-free in gfs2_glock_shrink_scan The GLF_LRU flag is checked under lru_lock in gfs2_glock_remove_from_lru() to remove the glock from the lru list in __gfs2_glock_put(). On the shrink scan path, the same flag is…
When was the CVE record for CVE-2021-47254 published?
The CVE record for CVE-2021-47254 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-2021-47254 actively exploited?
CVE-2021-47254 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (15th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-47254?
CVE-2021-47254 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2021-47254?
A fix for CVE-2021-47254 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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