CVE-2026-20040

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-03-11. a secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.8Exploit: NoneExposed: 0

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

A vulnerability in the CLI of Cisco IOS XR Software could allow an authenticated, local attacker to execute arbitrary commands as root on the underlying operating system of an affected device. This vulnerability is due to insufficient validation of user arguments that are passed to specific CLI commands. An attacker with a low-privileged account could exploit this vulnerability by using crafted commands at the prompt. A successful exploit could allow the attacker to elevate privileges to root and execute arbitrary commands on the underlying operating system.

CVSS v3
8.8
EG Score
8.8(medium)
EPSS
6.8%
KEV
Not listed

Published

March 11, 2026

Last Modified

July 1, 2026

Advisory Details (1)

Auto-updated Jul 2, 2026
No patch confirmed yet.
generic

Cisco IOS XR Software CLI Privilege Escalation Vulnerabilities

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-privesc-bF8D5U4W

Vendor Advisories for CVE-2026-20040(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 15× 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. 2026-07-12 05:46 UTCEPSS rescore
  2. 2026-07-12 05:46 UTCEPSS rescore
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-09 19:10 UTCEPSS rescore
  5. 2026-07-08 15:15 UTCEPSS rescore
  6. 2026-07-08 15:15 UTCEPSS rescore
  7. 2026-07-07 13:46 UTCEPSS rescore
  8. 2026-07-06 16:27 UTCEPSS rescore
  9. 2026-07-06 02:23 UTCEPSS rescore
  10. 2026-07-05 02:30 UTCEPSS rescore
  11. 2026-07-05 02:30 UTCEPSS rescore
  12. 2026-07-04 06:31 UTCEPSS rescore
  13. 2026-07-01 17:06 UTCEG score recompute
  14. 2026-07-01 17:06 UTCGHSA enrichment
  15. 2026-07-01 17:06 UTCNVD updatefirst tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-20040?
CVE-2026-20040 is a high vulnerability published on March 11, 2026. A vulnerability in the CLI of Cisco IOS XR Software could allow an authenticated, local attacker to execute arbitrary commands as root on the underlying operating system of an affected device. This vulnerability is due to insufficient validation of user arguments that are passed to specific CLI…
When was CVE-2026-20040 disclosed?
CVE-2026-20040 was first published in the National Vulnerability Database on March 11, 2026, with the most recent update on July 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-20040 actively exploited?
CVE-2026-20040 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 6.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-20040?
CVE-2026-20040 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-20040?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-20040, 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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