CVE-2021-1048

CRITICALNVD 7.89.0
EchelonGraph scoreHIGH confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2022-05-23), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 7.8 retained for reference. The 9.0 is the floor for confirmed exploitation, not an impact rating: this CVE's impact severity (EG Severity) is CVSS 7.8 HIGH under GitHub Security Advisory CVSS. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: CISA Known Exploited Vulnerabilities catalog, EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this weekExploited in the wild

Also known asEUVD-2021-6515 (ENISA EUVD) · GHSA-r535-rfwp-fm57 (GitHub Security Advisories)Source: ENISA EUVD

9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low or medium mission impact
CISA-KEV: ExploitedEPSS PROB: 1.1%CVSS: 7.8Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

In ep_loop_check_proc of eventpoll.c, there is a possible way to corrupt memory due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-204573007References: Upstream kernel

CVSS v3
7.8
EG Score
9.0CRITICALhigh confidence
EG Risk
75
EG Risk 75/100

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.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Attend at medium and Act at high mission impact.
Exploitation active (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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 at low, sooner than that at medium and as soon as possible at high mission impact.
EPSS PROB
1.1%
EPSS %ILE
64th
KEV
⚠ Exploited

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.0): severity, escalated by confirmed exploitation. This CVE's 9.0 is the CISA KEV floor for confirmed exploitation, not an impact rating: its impact severity (EG Severity) is CVSS 7.8 HIGH.

EG Severity
7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
1.1% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
CISA KEV and EG-KEV Tier 1 (exploited in the wild)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Attend at medium mission impactTrack at low, Attend at medium and Act at high mission impact.CISA BOD 26-04: 3 days & forensic triage if the affected system is publicly exposed; 14 days 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 low, Attend at medium and Act at high mission impact.

A fix is available. Apply it within your standard update timelines at low, sooner than that at medium and as soon as possible at high mission impact.

Exploitation active (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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)3 days & forensic triage if the affected system is publicly exposed; 14 days if it is not.

The score's inputs: In CISA KEV yes (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (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

CISA required action“Apply updates per vendor instructions.”

Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://nvd.nist.gov/vuln/detail/CVE-2021-1048

Published

December 15, 2021

Last Modified

October 23, 2025

Advisory Details (2)

Auto-updated Oct 26, 2026
⚠️ Actively exploited (CISA KEV, CISA Vulnrichment). Patch available. Sources: cisa.
CISA🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1048
Web page

Android Security Bulletin—November 2021  |  Android Open Source Project

https://source.android.com/security/bulletin/2021-11-01

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.8.10-1: fixed in 5.8.10-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.8.10-1: fixed in 5.8.10-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.8.10-1: fixed in 5.8.10-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 5.8.10-1: fixed in 5.8.10-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 21× in last 7d / 138× 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 100 of 1,256 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. None are among the latest 100 rows. The 1,156 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:37 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  2. 2026-11-02 11:16 UTCEG score recompute
  3. 2026-11-02 11:16 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  4. 2026-11-01 16:29 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  5. 2026-11-01 11:02 UTCEG score recompute
  6. 2026-11-01 11:02 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  7. 2026-10-31 16:28 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  8. 2026-10-31 10:48 UTCEG score recompute
  9. 2026-10-31 10:48 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  10. 2026-10-30 16:29 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  11. 2026-10-30 10:34 UTCEG score recompute
  12. 2026-10-30 10:34 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  13. 2026-10-29 16:29 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  14. 2026-10-29 10:20 UTCEG score recompute
  15. 2026-10-29 10:20 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  16. 2026-10-28 16:28 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  17. 2026-10-28 10:06 UTCEG score recompute
  18. 2026-10-28 10:06 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  19. 2026-10-27 16:28 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  20. 2026-10-27 09:51 UTCEG score recompute
  21. 2026-10-27 09:51 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  22. 2026-10-26 16:27 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  23. 2026-10-26 09:37 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  24. 2026-10-25 18:37 UTCEG score recompute
  25. 2026-10-25 16:28 UTCEPSS rescoreEPSS 1.1% · 64th percentile
Show 75 more
  1. 2026-10-25 09:24 UTCEG score recompute
  2. 2026-10-25 09:24 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  3. 2026-10-24 16:28 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  4. 2026-10-24 09:10 UTCEG score recompute
  5. 2026-10-24 09:10 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  6. 2026-10-23 16:28 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  7. 2026-10-23 08:56 UTCEG score recompute
  8. 2026-10-23 08:56 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  9. 2026-10-22 16:29 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  10. 2026-10-22 08:42 UTCEG score recompute
  11. 2026-10-22 08:41 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  12. 2026-10-21 16:28 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  13. 2026-10-21 08:27 UTCEG score recompute
  14. 2026-10-21 08:27 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  15. 2026-10-20 16:28 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  16. 2026-10-20 08:13 UTCEG score recompute
  17. 2026-10-20 08:13 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  18. 2026-10-19 16:28 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  19. 2026-10-19 07:58 UTCEG score recompute
  20. 2026-10-19 07:58 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  21. 2026-10-18 16:28 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  22. 2026-10-18 07:44 UTCEG score recompute
  23. 2026-10-18 07:44 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  24. 2026-10-17 16:28 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  25. 2026-10-17 07:29 UTCEG score recompute
  26. 2026-10-17 07:29 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  27. 2026-10-16 16:33 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  28. 2026-10-16 07:15 UTCEG score recompute
  29. 2026-10-16 07:15 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  30. 2026-10-15 16:28 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  31. 2026-10-15 07:01 UTCEG score recompute
  32. 2026-10-15 07:01 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  33. 2026-10-14 16:28 UTCEPSS rescoreEPSS 1.0% · 63rd percentile
  34. 2026-10-14 06:47 UTCEG score recompute
  35. 2026-10-14 06:47 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  36. 2026-10-13 16:28 UTCEPSS rescoreEPSS 1.0% · 63rd percentile
  37. 2026-10-13 06:31 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  38. 2026-10-12 19:27 UTCEG score recompute
  39. 2026-10-12 16:29 UTCEPSS rescoreEPSS 1.0% · 63rd percentile
  40. 2026-10-12 06:15 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  41. 2026-10-12 02:35 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  42. 2026-10-11 22:56 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  43. 2026-10-11 19:17 UTCEG score recompute
  44. 2026-10-11 19:17 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  45. 2026-10-11 15:40 UTCEG score recompute
  46. 2026-10-11 15:40 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  47. 2026-10-11 13:43 UTCEPSS rescoreEPSS 1.0% · 63rd percentile
  48. 2026-10-11 12:03 UTCEG score recompute
  49. 2026-10-11 12:03 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  50. 2026-10-11 08:24 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  51. 2026-10-11 04:44 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  52. 2026-10-11 01:04 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  53. 2026-10-10 21:24 UTCEG score recompute
  54. 2026-10-10 21:23 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  55. 2026-10-10 19:56 UTCEPSS rescoreEPSS 1.0% · 63rd percentile
  56. 2026-10-10 17:44 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  57. 2026-10-10 14:07 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  58. 2026-10-10 10:29 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  59. 2026-10-10 06:52 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  60. 2026-10-10 03:15 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  61. 2026-10-09 23:37 UTCEG score recompute
  62. 2026-10-09 23:37 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  63. 2026-10-09 20:04 UTCEPSS rescoreEPSS 1.0% · 63rd percentile
  64. 2026-10-09 19:59 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  65. 2026-10-09 16:22 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  66. 2026-10-09 12:44 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  67. 2026-10-09 09:07 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  68. 2026-10-09 05:28 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  69. 2026-10-09 01:51 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  70. 2026-10-08 22:14 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  71. 2026-10-08 18:36 UTCEG score recompute
  72. 2026-10-08 18:36 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  73. 2026-10-08 16:39 UTCEPSS rescoreEPSS 1.0% · 63rd percentile
  74. 2026-10-08 14:58 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8
  75. 2026-10-08 11:21 UTCGHSA enrichmentGHSA-r535-rfwp-fm57 · GitHub severity HIGH · GitHub CVSS 7.8

Frequently asked(6)

What is CVE-2021-1048?
CVE-2021-1048 is a critical-severity vulnerability; its CVE record was published on December 15, 2021. In ep_loop_check_proc of eventpoll.c, there is a possible way to corrupt memory due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid…
When was the CVE record for CVE-2021-1048 published?
The CVE record for CVE-2021-1048 was published on December 15, 2021. 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 October 23, 2025; the record at its source may have been updated since.
Is CVE-2021-1048 actively exploited?
Yes. CISA added CVE-2021-1048 to the Known Exploited Vulnerabilities catalog on May 23, 2022, affecting Android Kernel. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. A fix is available. Apply it.
What is the CVSS score of CVE-2021-1048?
CVE-2021-1048 has a CVSS v3 base score of 7.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
Which products are affected by CVE-2021-1048?
CVE-2021-1048 affects Android Kernel. The affected packages EchelonGraph has on record, with version ranges, are listed in the Affected Packages section of this page.
How do I remediate CVE-2021-1048?
A fix for CVE-2021-1048 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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