CVE-2021-3490

HIGHNVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.8 under NVD CVSS v3. EPSS exploit probability: 27.5%, top 2% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this weekWeaponized
7.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 27%CVSS: 7.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

The eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the Linux kernel did not properly update 32-bit bounds, which could be turned into out of bounds reads and writes in the Linux kernel and therefore, arbitrary code execution. This issue was fixed via commit 049c4e13714e ("bpf: Fix alu32 const subreg bound tracking on bitwise operations") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. The AND/OR issues were introduced by commit 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") (5.7-rc1) and the XOR variant was introduced by 2921c90d4718 ("bpf:Fix a verifier failure with xor") ( 5.10-rc1).

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
66(Track)
EG Risk 66/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity78% × 45%
Exploitation65% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
97.9%
KEV
Not listed

Published

June 4, 2021

Last Modified

November 21, 2024

References (14)

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 45× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-07-24 14:15 UTCEPSS rescore
  2. 2026-07-23 14:16 UTCEPSS rescore
  3. 2026-07-23 02:01 UTCEG score recompute
  4. 2026-07-22 22:48 UTCEG score recompute
  5. 2026-07-22 14:06 UTCEPSS rescore
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  10. 2026-07-18 18:59 UTCOSV refresh
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  1. 2026-07-08 15:12 UTCEPSS rescore
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  12. 2026-07-01 02:18 UTCOSV refresh
  13. 2026-06-30 23:20 UTCEPSS rescore
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  39. 2026-06-13 04:13 UTCOSV refresh
  40. 2026-06-12 23:10 UTCEPSS rescore
  41. 2026-06-11 13:58 UTCEPSS rescore
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  43. 2026-06-10 22:16 UTCEPSS rescore
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  45. 2026-06-10 13:20 UTCEPSS rescore
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  48. 2026-06-06 13:46 UTCEPSS rescore
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  63. 2026-05-29 13:42 UTCEPSS rescore
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  66. 2026-05-27 13:39 UTCEPSS rescore
  67. 2026-05-27 13:39 UTCEPSS rescore
  68. 2026-05-26 15:29 UTCEG score recompute
  69. 2026-05-26 15:29 UTCGHSA enrichment
  70. 2026-05-26 13:42 UTCEPSS rescore
  71. 2026-05-26 13:42 UTCEPSS rescore
  72. 2026-05-25 08:16 UTCOSV refresh

Publicly available exploits

(3 references)

Working exploit code is in the public domain (1 Metasploit module) (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCpivik271/CVE-2021-3490
    First seen Apr 6, 2023
    Open source ↗
  • GitHub PoCchompie1337/Linux_LPE_eBPF_CVE-2021-3490
    First seen Jun 24, 2021
    Open source ↗
  • Metasploitexploit/linux/local/cve_2021_3490_ebpf_alu32_bounds_check_lpe✓ verified
    First seen May 11, 2021

    Linux eBPF ALU32 32-bit Invalid Bounds Tracking LPE

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-3490?
CVE-2021-3490 is a high vulnerability published on June 4, 2021. The eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the Linux kernel did not properly update 32-bit bounds, which could be turned into out of bounds reads and writes in the Linux kernel and therefore, arbitrary code execution. This issue was fixed via commit 049c4e13714e ("bpf: Fix…
When was CVE-2021-3490 disclosed?
CVE-2021-3490 was first published in the National Vulnerability Database on June 4, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-3490 actively exploited?
CVE-2021-3490 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 97.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-3490?
CVE-2021-3490 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2021-3490?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-3490, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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