CVE-2021-47338

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-2021-34343 (ENISA EUVD) · GHSA-m2r9-3c4r-qv68 (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:

fbmem: Do not delete the mode that is still in use

The execution of fb_delete_videomode() is not based on the result of the previous fbcon_mode_deleted(). As a result, the mode is directly deleted, regardless of whether it is still in use, which may cause UAF.

================================================================== BUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0 \ drivers/video/fbdev/core/modedb.c:924 Read of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962

CPU: 2 PID: 18962 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ... Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x137/0x1be lib/dump_stack.c:118 print_address_description+0x6c/0x640 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report+0x13d/0x1e0 mm/kasan/report.c:562 fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924 fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon.c:2746 fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 18960: kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track+0x3d/0x70 mm/kasan/common.c:56 kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0x108/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1541 [inline] slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574 slab_free mm/slub.c:3139 [inline] kfree+0xca/0x3d0 mm/slub.c:4121 fb_delete_videomode+0x56a/0x820 drivers/video/fbdev/core/modedb.c:1104 fb_set_var+0x1f3/0xdb0 drivers/video/fbdev/core/fbmem.c:978 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9

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
19th
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

May 21, 2024

Last Modified

August 5, 2026

Advisory Details (5)

Auto-updated Aug 5, 2026
Patch available.
Web page

fbmem: Do not delete the mode that is still in use - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0af778269a522c988ef0b4188556aba97fb420cc
Web page

fbmem: Do not delete the mode that is still in use - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d6e76469157d8f240e5dec6f8411aa8d306b1126
Web page

fbmem: Do not delete the mode that is still in use - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f193509afc7ff37a46862610c93b896044d5b693
Web page

fbmem: Do not delete the mode that is still in use - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/087bff9acd2ec6db3f61aceb3224bde90fe0f7f8
Web page

fbmem: Do not delete the mode that is still in use - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/359311b85ebec7c07c3a08ae2f3def946cad33fa

Vendor Advisories for CVE-2021-47338(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatkernel-rt-0:4.18.0-553.22.1.rt7.363.el8_102024-09-24redhat
redhatkernel-0:4.18.0-553.22.1.el8_102024-09-24redhat

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
linux5.10.46-4, 5.10.46-5, 5.10.70-1~bpo10+1
  • every version up to 5.10.70-1: fixed in 5.10.70-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.14.6-1: fixed in 5.14.6-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.14.6-1: fixed in 5.14.6-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.14.6-1: fixed in 5.14.6-1
—

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 220 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 123 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:30 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  2. 2026-10-31 16:29 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  3. 2026-10-30 16:30 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  4. 2026-10-29 16:29 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  5. 2026-10-28 21:46 UTCEG score recompute
  6. 2026-10-28 21:46 UTCVendor advisory
  7. 2026-10-28 21:45 UTCGHSA enrichmentGHSA-m2r9-3c4r-qv68 · GitHub severity HIGH · GitHub CVSS 7.8
  8. 2026-10-28 16:28 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  9. 2026-10-27 16:28 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  10. 2026-10-26 16:28 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  11. 2026-10-25 18:18 UTCEG score recompute
  12. 2026-10-25 16:29 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  13. 2026-10-24 16:29 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  14. 2026-10-23 16:28 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  15. 2026-10-22 16:29 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  16. 2026-10-21 16:28 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  17. 2026-10-21 08:33 UTCEG score recompute
  18. 2026-10-21 08:33 UTCVendor advisory
  19. 2026-10-21 08:33 UTCGHSA enrichmentGHSA-m2r9-3c4r-qv68 · GitHub severity HIGH · GitHub CVSS 7.8
  20. 2026-10-20 16:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  21. 2026-10-19 16:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  22. 2026-10-19 12:55 UTCOSV refresh
  23. 2026-10-18 16:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  24. 2026-10-18 08:49 UTCEG score recompute
  25. 2026-10-17 16:29 UTCEPSS rescoreEPSS 0.3% · 17th percentile
Show 72 more
  1. 2026-10-16 16:34 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  2. 2026-10-15 16:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  3. 2026-10-14 16:29 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  4. 2026-10-13 16:28 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  5. 2026-10-12 19:05 UTCEG score recompute
  6. 2026-10-12 16:30 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  7. 2026-10-11 23:31 UTCEG score recompute
  8. 2026-10-11 13:44 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  9. 2026-10-10 19:56 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  10. 2026-10-09 20:04 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  11. 2026-10-08 16:40 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  12. 2026-10-07 23:45 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  13. 2026-10-06 15:14 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  14. 2026-10-05 17:40 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  15. 2026-10-04 23:19 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  16. 2026-10-03 14:22 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  17. 2026-10-02 16:23 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  18. 2026-09-30 15:45 UTCEG score recompute
  19. 2026-09-30 15:00 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  20. 2026-09-29 15:15 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  21. 2026-09-28 13:47 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  22. 2026-09-26 20:03 UTCOSV refresh
  23. 2026-09-26 15:54 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  24. 2026-09-26 00:21 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  25. 2026-09-24 14:00 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  26. 2026-09-23 13:45 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  27. 2026-09-22 14:44 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  28. 2026-09-21 20:28 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  29. 2026-09-20 20:13 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  30. 2026-09-19 15:38 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  31. 2026-09-18 19:24 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  32. 2026-09-17 19:23 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  33. 2026-09-16 14:05 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  34. 2026-09-15 03:06 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  35. 2026-09-12 14:57 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  36. 2026-09-11 14:49 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  37. 2026-09-11 09:33 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  38. 2026-09-08 21:57 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  39. 2026-09-07 05:17 UTCOSV refresh
  40. 2026-09-06 13:45 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  41. 2026-09-05 15:25 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  42. 2026-09-04 13:57 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  43. 2026-09-04 05:03 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  44. 2026-09-02 14:09 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  45. 2026-09-01 13:51 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  46. 2026-08-30 19:14 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  47. 2026-08-30 01:19 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  48. 2026-08-28 21:38 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  49. 2026-08-27 14:22 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  50. 2026-08-26 14:43 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  51. 2026-08-25 13:46 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  52. 2026-08-24 14:13 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  53. 2026-08-21 23:46 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  54. 2026-08-20 22:52 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  55. 2026-08-20 15:01 UTCOSV refresh
  56. 2026-08-19 17:01 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  57. 2026-08-18 13:45 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  58. 2026-08-17 13:44 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  59. 2026-08-16 14:53 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  60. 2026-08-16 02:11 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  61. 2026-08-15 01:27 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  62. 2026-08-13 21:57 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  63. 2026-08-12 13:48 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  64. 2026-08-11 13:38 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  65. 2026-08-09 13:44 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  66. 2026-08-08 16:34 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  67. 2026-08-07 16:24 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  68. 2026-08-06 13:44 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  69. 2026-08-05 19:15 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  70. 2026-08-05 09:40 UTCEG score recompute
  71. 2026-08-05 09:40 UTCVendor advisory
  72. 2026-08-05 09:40 UTCGHSA enrichmentGHSA-m2r9-3c4r-qv68 · GitHub severity HIGH · GitHub CVSS 7.8

Frequently asked(5)

What is CVE-2021-47338?
CVE-2021-47338 is a high-severity vulnerability; its CVE record was published on May 21, 2024. In the Linux kernel, the following vulnerability has been resolved: fbmem: Do not delete the mode that is still in use The execution of fb_delete_videomode() is not based on the result of the previous fbcon_mode_deleted(). As a result, the mode is directly deleted, regardless of whether it is still…
When was the CVE record for CVE-2021-47338 published?
The CVE record for CVE-2021-47338 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-2021-47338 actively exploited?
CVE-2021-47338 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (19th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-47338?
CVE-2021-47338 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2021-47338?
A fix for CVE-2021-47338 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2021-47338 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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