CVE-2026-20277

HIGHPre-NVD 8.28.2—
EchelonGraph scoreHIGH confidence

Score 8.2 from GitHub Security Advisory (severity: HIGH) published 2026-09-02. the CNA's CVSS baseline 8.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:cisco, epss, ghsa
Trending — 3 sources updated this week
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.2Exploit: None knownExposed: 0

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

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XR Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20277 are related to protection mechanism failure issues that are grouped under the Common Weakness Enumeration (CWE) CWE-693.

CVSS v3
8.2
EG Score
8.2(high)
EG Risk
52(Track)
EG Risk 52/100SSVC: 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
Severity82% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
12%
KEV
Not listed

Published

September 2, 2026

Last Modified

September 9, 2026

Advisory Details (1)

Auto-updated Sep 2, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic🔴 Active Exploitation

Cisco IOS XR Software Security Hardening Release: September 2026

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-iosxr-qg64NcM

Vendor Advisories for CVE-2026-20277(2)

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 28× in last 7d / 40× 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. 2026-09-11 17:26 UTCEG score recompute
  2. 2026-09-11 17:26 UTCGHSA enrichment
  3. 2026-09-11 14:52 UTCEPSS rescore
  4. 2026-09-11 09:36 UTCEPSS rescore
  5. 2026-09-11 05:21 UTCGHSA enrichment
  6. 2026-09-10 17:54 UTCEG score recompute
  7. 2026-09-10 17:54 UTCGHSA enrichment
  8. 2026-09-10 09:34 UTCEPSS rescore
  9. 2026-09-10 06:27 UTCGHSA enrichment
  10. 2026-09-09 19:00 UTCGHSA enrichment
  11. 2026-09-09 10:39 UTCGHSA enrichment
  12. 2026-09-08 23:12 UTCEG score recompute
  13. 2026-09-08 23:11 UTCGHSA enrichment
  14. 2026-09-08 22:00 UTCEPSS rescore
  15. 2026-09-08 09:59 UTCGHSA enrichment
  16. 2026-09-07 22:19 UTCEG score recompute
  17. 2026-09-07 22:19 UTCGHSA enrichment
  18. 2026-09-07 16:01 UTCEPSS rescore
  19. 2026-09-07 10:51 UTCGHSA enrichment
  20. 2026-09-06 23:15 UTCEG score recompute
  21. 2026-09-06 23:15 UTCGHSA enrichment
  22. 2026-09-06 13:47 UTCEPSS rescore
  23. 2026-09-06 11:48 UTCGHSA enrichment
  24. 2026-09-06 00:21 UTCEG score recompute
  25. 2026-09-06 00:21 UTCGHSA enrichment
Show 15 more
  1. 2026-09-05 12:50 UTCGHSA enrichment
  2. 2026-09-05 01:21 UTCEG score recompute
  3. 2026-09-05 01:21 UTCGHSA enrichment
  4. 2026-09-04 13:54 UTCEG score recompute
  5. 2026-09-04 13:54 UTCGHSA enrichment
  6. 2026-09-04 05:06 UTCEPSS rescore
  7. 2026-09-04 04:24 UTCGHSA enrichment
  8. 2026-09-03 16:55 UTCGHSA enrichment
  9. 2026-09-03 06:06 UTCGHSA enrichment
  10. 2026-09-02 18:36 UTCEG score recompute
  11. 2026-09-02 18:36 UTCGHSA enrichment
  12. 2026-09-02 18:06 UTCEG score recompute
  13. 2026-09-02 17:37 UTCEG score recompute
  14. 2026-09-02 16:33 UTCEG score recompute
  15. 2026-09-02 16:31 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-20277?
CVE-2026-20277 is a high vulnerability published on September 2, 2026. As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XR Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening releases that address multiple internally discovered vulnerabilities. The…
When was CVE-2026-20277 disclosed?
CVE-2026-20277 was first published in the National Vulnerability Database on September 2, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-20277 actively exploited?
CVE-2026-20277 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 87.6% of all scored CVEs.
What is the CVSS score of CVE-2026-20277?
CVE-2026-20277 has a CVSS v4.0 base score of 8.2 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-20277?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-20277, 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

Explore the affected products and dependency analysis for CVE-2026-20277

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