CVE-2021-1266

MEDIUMNVD 4.34.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.3 under NVD CVSS v3. EPSS exploit probability: 1.1%, top 37% 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
4.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 4.3Exploit: NoneExposed: 0

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

A vulnerability in the REST API of Cisco Managed Services Accelerator (MSX) could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to the way that the affected software logs certain API requests. An attacker could exploit this vulnerability by sending a flood of crafted API requests to an affected device. A successful exploit could allow the attacker to cause a DoS condition on the affected device.

CVSS v3
4.3
EG Score
4.3(medium)
EG Risk
20(Track)
EG Risk 20/100SSVC: 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
Severity43% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
63.3%
KEV
Not listed

Published

February 4, 2021

Last Modified

November 21, 2024

References (2)

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 41× 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. 2026-07-23 14:15 UTCEPSS rescore
  2. 2026-07-23 01:56 UTCEG score recompute
  3. 2026-07-22 22:42 UTCEG score recompute
  4. 2026-07-22 14:05 UTCEPSS rescore
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  1. 2026-07-05 02:28 UTCEPSS rescore
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  64. 2026-05-27 13:39 UTCEPSS rescore
  65. 2026-05-26 21:20 UTCEG score recompute
  66. 2026-05-26 21:20 UTCGHSA enrichment
  67. 2026-05-26 13:42 UTCEPSS rescore
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  71. 2026-05-25 12:16 UTCOSV refresh
  72. 2026-05-24 16:49 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-1266?
CVE-2021-1266 is a medium vulnerability published on February 4, 2021. A vulnerability in the REST API of Cisco Managed Services Accelerator (MSX) could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to the way that the affected software logs certain API requests. An attacker could…
When was CVE-2021-1266 disclosed?
CVE-2021-1266 was first published in the National Vulnerability Database on February 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-2021-1266 actively exploited?
CVE-2021-1266 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 63.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-1266?
CVE-2021-1266 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2021-1266?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-1266, 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.

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