A vulnerability in the sftunnel functionality of Cisco Secure Firewall Management Center (FMC) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with administrative privileges to write arbitrary files as root on the underlying operating system. This vulnerability is due to insufficient validation of the directory path during file synchronization. An attacker could exploit this vulnerability by crafting a directory path outside of the expected file location. A successful exploit could allow the attacker to create or replace any file on the underlying operating system.
CVE-2026-20018
MEDIUMPre-NVD 5.95.9—Trending — 3 sources updated this week
EchelonGraph scoreMEDIUM confidence
Score 5.9 from GitHub Security Advisory published 2026-03-04. the CNA's CVSS baseline 5.9; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: cna:cisco, ghsa
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.9
- EG Score
- 5.9(medium)
- EG Risk
- 27(Track)EG Risk 27/100SSVC: 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 computedSeverity59% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 35%
- KEV
- Not listed
Published
March 4, 2026
Last Modified
June 17, 2026
References (1)
Vendor Advisories for CVE-2026-20018(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 5× in last 7d / 5× 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.
- 2026-08-01 04:15 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-27 14:13 UTCEPSS rescore
- 2026-07-27 12:54 UTCEG score recompute
- 2026-07-27 12:54 UTCGHSA enrichment
Frequently asked(5)
What is CVE-2026-20018?
CVE-2026-20018 is a medium vulnerability published on March 4, 2026. A vulnerability in the sftunnel functionality of Cisco Secure Firewall Management Center (FMC) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with administrative privileges to write arbitrary files as root on the underlying operating…
When was CVE-2026-20018 disclosed?
CVE-2026-20018 was first published in the National Vulnerability Database on March 4, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-20018 actively exploited?
CVE-2026-20018 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 65.4% of all scored CVEs.
What is the CVSS score of CVE-2026-20018?
CVE-2026-20018 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-20018?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-20018, 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-2026-20018
Is Your Infrastructure Affected by CVE-2026-20018?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.